Automated unloading and loading robot system

ABSTRACT

A system includes a robot configured to load and/or unload from a location, such as a cargo carrier or building. The robot includes a base unit that has a transport system to move the base unit. A mast extends from the base unit, and the mast has a mast conveyor. An End of Arm Tool (EoAT) is coupled to the mast. The EoAT includes an EoAT conveyor configured to move a cargo item to and from the mast conveyor. A gripper mechanism is configured to move between a retracted position where the gripper mechanism is clear of the cargo item on the EoAT conveyor and an extended position where the gripper mechanism is able to grip the cargo item.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/795,947, filed Oct. 27, 2017, which is hereby incorporated byreference. U.S. patent application Ser. No. 15/795,947, filed Oct. 27,2017, claims the benefit of U.S. patent application No. 62/413,602,filed Oct. 27, 2016, which are hereby incorporated by reference.

BACKGROUND

Loading and unloading cargo, such as packages, boxes, bags, cans, and/orother products, from the cargo containers, such as trailers, cargocarriers, and the like, can be quite expensive, labor-intensive, andeven dangerous at times. Often the shipping and receiving operations atthe loading docks are the bottlenecks for the entire fulfillmentoperation. Stacking and unstacking cargo items in warehouses andmanufacturing plants can be likewise expensive and dangerous. Highstacks of cargo items can become unstable so as to readily fall on thosehandling the cargo. Manually loading and unloading a trailer can be atough job because of the environmental conditions inside the trailer. Insummer, the trailer can become extremely hot, and in the winter, it canbe quite cold. It is also a physically demanding job. For example,personnel in some cases need to manually lift very heavy cargo itemsapproaching 50 pounds in weight over an eight hour shift, and reachingfor such items when stacked high can be back breaking work. In suchphysically demanding jobs, employee turnover is high, and workercompensation claims are likewise high.

Often forklift trucks have been used to load pallets of items to andfrom cargo containers and warehouses, but there are a number oflimitations on their use. For example, semitrailers have been known todislodge from loading docks which can be especially dangerous forforklift truck operators. Moreover, the loading or unloading processtypically takes a considerable amount of time because usually only oneforklift can fit inside the trailer at a time. In addition, the palletsfor the forklifts typically waste usable space within the cargocontainer and add unnecessary weight. This wasted empty space and addedweight costs money. When difficulties arise with the forklifts, loadingdock personnel have been used to manually unload and stack items withinthe cargo space, but again such labor intensive activities can still bequite expensive and time-consuming as well as can result in injury tothe personnel. Robotic and other automated systems have been proposedfor loading and unloading cargo, but these systems still have a numberof significant drawbacks. The throughput provided by these systems istypically low, and these systems are error prone, thereby stillrequiring human intervention when mishaps occur. Thus, there is a needfor improvement in this field.

SUMMARY

An automated unloading and loading robot system has been developed torapidly stack and/or unstack cargo items in a cargo carrier (or otherlocation). The system includes a mobile robot that has a unique End ofArm Tool (EoAT) attached to a moveable mast. The EoAT incorporates aconveyor system that is able to rapidly transport the cargo items on anear continuous basis. The EoAT includes an extendable-retractablegripper mechanism that is configured to grip the cargo items. In oneform, the gripper mechanism includes one or more vacuum cups to grip thecargo items. The gripper mechanism is able to extend the vacuum cupsabove the conveyor system on the EoAT in order to pull cargo onto theconveyor system. Once the cargo item is pulled onto the conveyor system,the vacuum cups are retracted below the conveyor system so that thecargo item is able to travel over the gripper mechanism. When unloadingor stacking the cargo items, the gripper mechanism can operate in areverse fashion and accurately push the cargo items from the conveyorsystem and onto the cargo stack. The EoAT is able to move in yaw(side-to-side) and pitch (tilt) directions relative to the mast so thatit is properly positioned to pick or place the cargo items. The mast isattached to a mobile base unit. The mobile base unit is able to move theEoAT by moving the mast. In addition, large or major movements of theEoAT can be accomplished by moving and/or steering the mobile base unit.For example, the mobile base unit is configured to move in and out of atrailer as well as in side-to-side directions. The moveable mastminimizes the distance the base unit needs to move in order to load orunload the cargo items from the cargo container. The base unit is ableto adjust the yaw and pitch of the mast. The base unit is also able toextend and retract the mast so that the base unit does not need to moveas the EoAT moves vertically and horizontally along a row of stackedcargo items. The mast and base unit have conveyors for transporting thecargo items to and from the EoAT. In one form, an extendable conveyor iscoupled to the base unit so as to form a link between the robot and mainconveyor system in a facility. This robot system can rapidly load andunload cargo carriers automatically with no or little human interaction.This system design eliminates the need for forklift operators which inturn reduces the risk of injury and expense associated with theoperators as well as reduces loading and unloading times.

Aspect 1 concerns a system, comprising a robot including a base unithaving a transport system to move the base unit, a mast extending fromthe base unit, the mast having a mast conveyor, and an End of Arm Tool(EoAT) coupled to the mast, wherein the EoAT includes an EoAT conveyorconfigured to move a cargo item to and from the mast conveyor, and agripper mechanism configured to move between a retracted position wherethe gripper mechanism is clear of the cargo item on the EoAT conveyorand an extended position where the gripper mechanism is able to grip thecargo item.

Aspect 2 concerns the aspect of any preceding aspect, wherein thegripper mechanism is at or underneath the EoAT conveyor to facilitateunobstructed movement of the cargo item along the EoAT conveyor when inthe retracted position; and the gripper mechanism is raised above theEoAT conveyor to grip the cargo item when in the extended position.

Aspect 3 concerns the aspect of any preceding aspect, wherein thegripper mechanism includes a carriage, an extension mechanism coupled tothe carriage to vertically extend the gripper mechanism relative to theEoAT conveyor; and a gripping section coupled to the extensionmechanism, wherein the gripping section is configured to grip the cargoitem.

Aspect 4 concerns the aspect of any preceding aspect, wherein the EoATincludes a cam track along which the carriage rides, wherein the camtrack is shaped to guide the extension mechanism to move the grippingmechanism between the retracted position and the extended position; anda drive track coupled to the carriage to guide the carriage in alongitudinal direction along the cam track to move the gripper mechanismbetween the retracted position and the extended position.

Aspect 5 concerns the aspect of any preceding aspect, wherein thecarriage includes a cam follower coupled to the extension mechanism; andthe cam follower rides along the cam track as the carriage moves in alongitudinal direction along the cam track.

Aspect 6 concerns the aspect of any preceding aspect, wherein the camtrack includes a retracted section where the gripper mechanism ispositioned at the retracted position an engagement section where thegripper mechanism is at the extended position; and a transition sectionlocated between the retracted section and the engagement section.

Aspect 7 concerns the aspect of any preceding aspect, wherein the EoAThas a mast facing end where the EoAT is coupled to the mast and a cargofacing end located opposite the mast facing end; and the cam trackincludes an extended section configured to lower the gripper mechanismrelative to the EoAT conveyor when at the cargo facing end.

Aspect 8 concerns the aspect of any preceding aspect, wherein the camtrack tapers from the mast facing end to the cargo facing end; and thedrive track tapers from the mast facing end to the cargo facing end.

Aspect 9 concerns the aspect of any preceding aspect, wherein theextension mechanism includes one or more extension linkages pivotallycoupled between the carriage and the gripper mechanism.

Aspect 10 concerns the aspect of any preceding aspect, wherein the oneor more extension linkages are oriented in a parallelogram linkage typearrangement with the carriage and the gripper mechanism.

Aspect 11 concerns the aspect of any preceding aspect, wherein theextension mechanism includes a biasing spring to bias the grippermechanism towards the retracted position.

Aspect 12 concerns the aspect of any preceding aspect, wherein the EoATincludes a gripper drive configured to move the gripper mechanism in thelongitudinal direction along the drive track.

Aspect 13 concerns the aspect of any preceding aspect, wherein thegripper drive includes a reversible motor; and a gripper drive beltoperatively connecting the gripper drive to the carriage.

Aspect 14 concerns the aspect of any preceding aspect, wherein the drivetrack defines a guide slot; and the carriage includes a drive wheelrecited in the guide slot.

Aspect 15 concerns the aspect of any preceding aspect, wherein the EoATconveyor includes a belt type conveyor.

Aspect 16 concerns the aspect of any preceding aspect, wherein the EoATincludes one or more guide rails that have a flared shape.

Aspect 17 concerns the aspect of any preceding aspect, wherein thegripper mechanism includes at least two vacuum cups; and each of thevacuum cups has a vacuum control valve that operates independently ofthe other vacuum cups.

Aspect 18 concerns the aspect of any preceding aspect, wherein thegripper mechanism includes one or more vacuum cups to grip the cargoitem.

Aspect 19 concerns the aspect of any preceding aspect, wherein the robotincludes an EoAT pitch-yaw joint connecting the EoAT to the mast; andthe EoAT pitch-yaw joint being configured to move the EoAT in a pitchdirection and/or a yaw direction.

Aspect 20 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes a yaw pivot shaft, a pivot block defining ashaft channel through which the yaw pivot shaft extends, a rack gearrotatably coupled to the yaw pivot shaft to rotate around the yaw pivotshaft; and a pinion gear engaging the rack gear at a position traverseto the rack gear.

Aspect 21 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes an EoAT bracket connected to the EoAT, the EoATbracket has at least a pair of flanges that define a bracket cavity inwhich the pivot block is disposed, and the yaw pivot shaft extendsbetween the flanges.

Aspect 22 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes a pitch driveshaft secured to the pivot blockin a fixed manner a pitch drive pulley secured to the pitch driveshaftto move the EoAT in the pitch direction when rotated; and a yaw drivegear coupled to the pinion gear in a fixed manner, wherein the yaw drivegear is rotatably coupled to the pitch driveshaft to move the EoAT inthe yaw direction when rotated about the pitch driveshaft.

Aspect 23 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes a second pinion gear engaging the rack gear ata second position traverse to the rack gear, wherein the second piniongear is positioned opposite the pinion gear with the yaw pivot shaftlocated in between a first pulley connected to the pinion to rotate thepinion a second pulley connected to the second pinion to rotate thesecond pinion wherein the rack gear is secured in a fixed manner to oneof the pair of flanges wherein the pivot block defines a rack cavity inwhich the rack gear is disposed, a first pinion cavity in which thepinion is disposed, a second pinion cavity in which the second pinion isdisposed, a first gear engagement channel extending between the rackcavity and the first pinion cavity, and a second gear engagement channelextending between the rack cavity and the second pinion cavity whereinthe pinion and the second pinion are configured to move the EoAT in thepitch direction when rotated in a same direction; and wherein the pinionand the second pinion are configured to move the EoAT in the yawdirection when rotated in an opposite direction.

Aspect 24 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes a second pinion gear engaging the rack gear ata second position traverse to the rack gear, wherein the second piniongear is positioned opposite the pinion gear with the yaw pivot shaftlocated in between.

Aspect 25 concerns the aspect of any preceding aspect, wherein the robotincludes a mast actuator system configured to move the mast in a yawdirection, a pitch direction, and/or a longitudinal direction.

Aspect 26 concerns the aspect of any preceding aspect, wherein the mastactuator system includes a mast yaw control subsystem coupled to thebase unit to control movement of the mast in the yaw direction; and amast pitch control subsystem coupled to the mast yaw control subsystemto control movement of the mast in the pitch direction and thelongitudinal direction.

Aspect 27 concerns the aspect of any preceding aspect, wherein the mastyaw control subsystem includes a mast base rotatably coupled to the baseunit, wherein the mast pitch control subsystem is supported by the mastbase; and a mast yaw drive motor secured to the base unit, wherein themast yaw drive is coupled to the mast base to rotate the mast base inthe yaw direction relative to the base unit.

Aspect 28 concerns the aspect of any preceding aspect, wherein the mastyaw control subsystem includes a mast yaw drive gearbox mounted to thebase unit; and wherein the mast yaw drive gearbox operatively couplesthe mast yaw drive motor to the mast base.

Aspect 29 concerns the aspect of any preceding aspect, wherein the mastpitch control subsystem includes a mast extension arm pivotally coupledbetween the mast base and the mast, wherein the mast extension arm isconfigured to pivot to cause the mast and the EoAT to move horizontallyin the longitudinal direction; and a mast pitch arm pivotally coupledbetween the mast base the mast, wherein the mast pitch arm is configuredto move to control movement the mast in the pitch direction.

Aspect 30 concerns the aspect of any preceding aspect, wherein the mastpitch control subsystem includes an extension drive mounted to the mastbase an extension crank coupled to the extension drive an extension linkconnecting the extension crank to the mast extension arm wherein theextension drive is configured to rotate the extension crank to pivot themast extension arm a pitch drive mounted to the mast base a pitch crankcoupled to the pitch drive wherein the mast pitch arm is pivotallycoupled to the pitch crank; and wherein the pitch drive is configured torotate the pitch crank to move the mast pitch arm.

Aspect 31 concerns the aspect of any preceding aspect, furthercomprising a counterbalance system coupled to the mast to counterbalancethe weight of the mast.

Aspect 32 concerns the aspect of any preceding aspect, wherein thecounterbalance system includes an air spring coupled to the mast.

Aspect 33 concerns the aspect of any preceding aspect, furthercomprising a base unit conveyor operatively connecting the base unit andthe mast to transport the cargo item between the mast and a mainconveyor system, wherein the base unit conveyor has an extendable lengtha mast connection joint connecting the base unit conveyor to the mast,wherein the mast connection joint is configured to allowmultidirectional movement between the base unit conveyor and the mast;and a base connection joint connecting the base unit conveyor to thebase unit, wherein the base unit connection joint is configured to allowmovement of the base unit conveyor in the yaw direction and the pitchdirection.

Aspect 34 concerns the aspect of any preceding aspect, furthercomprising a base unit conveyor operatively connecting the base unit andthe mast, wherein the base unit conveyor is configured to extend in atelescoping manner a mast connection joint connecting the base unitconveyor to the mast, wherein the mast connection joint is configured toallow multidirectional movement between the base unit conveyor and themast; and a base connection joint connecting the base unit conveyor tothe base unit, wherein the base unit connection joint is configured toallow movement of the base unit conveyor in the yaw direction and thepitch direction.

Aspect 35 concerns the aspect of any preceding aspect, wherein the baseunit conveyor includes a mast section connected to the mast via the mastconnection joint a transition section connected to the base unit via thebase unit connection joint, wherein the mast section and the transitionsection are nested together; and a telescoping joint connecting the mastsection to the transition section to allow the mast section to moverelative to the transition section in a telescoping manner.

Aspect 36 concerns the aspect of any preceding aspect, wherein the mastsection includes a mast section conveyor, and a mast section conveyormotor configured to power the mast section conveyor the transitionsection includes a transition section conveyor, and a transition sectionconveyor motor configured to power the transition section conveyor; andwherein the mast section conveyor motor and the transition sectionconveyor motor are configured to operate independently of each other.

Aspect 37 concerns the aspect of any preceding aspect, wherein the mastconnection joint includes a ball type joint to facilitate relativemovement between the mast and the base unit conveyor in both a pitchdirection and a yaw direction.

Aspect 38 concerns the aspect of any preceding aspect, wherein the baseconnection joint includes a turntable joint rotatably coupled to thebase unit a conveyor shaft bracket defining a shaft opening; and aconveyor shaft rotatably received in the shaft opening.

Aspect 39 concerns the aspect of any preceding aspect, wherein thetransport system includes one or more self-powered wheels configured torotate at least ninety-degrees (90°) relative to the base unit.

Aspect 40 concerns the aspect of any preceding aspect, furthercomprising a main conveyor system; and an extendable conveyor coupledbetween the robot and the main conveyor.

Aspect 41 concerns a system, comprising an End of Arm Tool (EoAT)including an EoAT conveyor configured to move a cargo item, a grippermechanism configured to move between a retracted position and anextended position, wherein the gripper mechanism includes one or morevacuum cups to grip the cargo item, wherein the gripper mechanism is ator underneath the EoAT conveyor to facilitate unobstructed movement ofthe cargo item along the EoAT conveyor when in the retracted position,and wherein the gripper mechanism is raised above the EoAT conveyor togrip the cargo item when in the extended position.

Aspect 42 concerns the aspect of any preceding aspect, wherein thegripper mechanism includes a carriage, an extension mechanism coupled tothe carriage to vertically extend the gripper mechanism relative to theEoAT conveyor, and a gripping section coupled to the extensionmechanism, wherein the gripping section is configured to grip the cargoitem.

Aspect 43 concerns the aspect of any preceding aspect, wherein the EoATincludes a cam track along which the carriage rides, wherein the camtrack is shaped to guide the extension mechanism to move the grippingmechanism between the retracted position and the extended position; anda drive track coupled to the carriage to guide the carriage in alongitudinal direction along the cam track to move the gripper mechanismbetween the retracted position and the extended position.

Aspect 44 concerns the aspect of any preceding aspect, wherein thecarriage includes a cam follower coupled to the extension mechanism; andthe cam follower rides along the cam track as the carriage moves in alongitudinal direction along the cam track.

Aspect 45 concerns the aspect of any preceding aspect, wherein the camtrack includes a retracted section where the gripper mechanism ispositioned at the retracted position an engagement section where thegripper mechanism is at the extended position; and a transition sectionlocated between the retracted section and the engagement section.

Aspect 46 concerns the aspect of any preceding aspect, furthercomprising an EoAT pitch-yaw joint connected to the EoAT; and the EoATpitch-yaw joint being configured to move the EoAT in a pitch directionand/or a yaw direction.

Aspect 47 concerns the aspect of any preceding aspect, wherein the EoATpitch-yaw joint includes a yaw pivot shaft a pivot block defining ashaft channel through which the yaw pivot shaft extends a rack gearrotatably coupled to the yaw pivot shaft to rotate around the yaw pivotshaft; and a pinion gear engaging the rack gear at a position traverseto the rack gear.

Aspect 48 concerns the aspect of any preceding aspect, furthercomprising a robot including a base unit having a transport system tomove the base unit, a mast extending from the base unit, the mast havinga mast conveyor, and the EoAT coupled to the mast.

Aspect 49 concerns a system, comprising an End of Arm Tool (EoAT) havingan EoAT conveyor, a mast having a mast conveyor, an EoAT pitch-yaw jointconnecting the EoAT to the mast, wherein the EoAT pitch-yaw joint isconfigured to move the EoAT in a pitch direction and/or a yaw directionto maintain alignment of the EoAT conveyor and the mast conveyor,wherein the EoAT pitch-yaw joint includes a yaw pivot shaft, a rack gearrotatably coupled to the yaw pivot shaft to rotate around the yaw pivotshaft, a first pinion gear engaging the rack gear at a position traverseto the rack gear, and a second pinion gear engaging the rack gear at asecond position traverse to the rack gear.

Aspect 50 concerns the aspect of any preceding aspect, wherein the mastconveyor includes a mast conveyor belt, and the EoAT pitch-yaw jointincludes a pivot housing a mast conveyor pulley rotatably coupled to thepivot housing, and wherein the mast conveyor belt engages the mastconveyor pulley.

Aspect 51 concerns a system, comprising a base unit having a transportsystem to move the base unit, a mast having a mast conveyor coupled tothe base unit a mast actuator system configured to move the mast in ayaw direction, a pitch direction, and/or a longitudinal directionrelative to the base unit, wherein the mast actuator system includes amast yaw control subsystem coupled to the base unit to control movementof the mast in the yaw direction, and a mast pitch control subsystemcoupled to the mast yaw control subsystem to control movement of themast in the pitch direction and the longitudinal direction.

Aspect 52 concerns the aspect of any preceding aspect, wherein the mastyaw control subsystem includes a mast base rotatably coupled to the baseunit, the mast pitch control subsystem is supported by the mast base;and a mast yaw drive motor secured to the base unit, wherein the mastyaw drive is coupled to the mast base to rotate the mast base in the yawdirection relative to the base unit.

Aspect 53 concerns the aspect of any preceding aspect, wherein the mastpitch control subsystem includes a mast extension arm pivotally coupledbetween the mast base and the mast, wherein the mast extension arm isconfigured to pivot to cause the mast and the EoAT to move horizontallyin the longitudinal direction; and a mast pitch arm pivotally coupledbetween the mast base and the mast, wherein the mast pitch arm isconfigured to move to control movement of the mast in the pitchdirection.

Aspect 54 concerns the aspect of any preceding aspect, furthercomprising a base unit conveyor operatively connecting the base unit andthe mast to transport a cargo item, wherein the base unit conveyor hasan extendable length a mast connection joint connecting the base unitconveyor to the mast, wherein the mast connection joint is configured toallow multidirectional movement between the base unit conveyor and themast; and a base connection joint connecting the base unit conveyor tothe base unit, wherein the base unit connection joint is configured toallow movement of the base unit conveyor in the yaw direction and thepitch direction.

Aspect 55 concerns a method of operating the system according to anypreceding claim.

Aspect 56 concerns a method, comprising positioning an End of Arm Tool(EoAT) proximal a cargo item, wherein the EoAT has an EoAT conveyor,wherein the gripper mechanism includes one or more vacuum cups securinga cargo item with the vacuum cups of the gripper mechanism pulling thecargo item onto the EoAT conveyor with the gripper mechanism by movingthe gripper mechanism along the EoAT retracting the gripper mechanism ator underneath the EoAT conveyor to a retracted position; and moving thecargo item with the EoAT conveyor over the gripper mechanism when in theretracted position.

Aspect 57 concerns the aspect of any preceding aspect, furthercomprising wherein said positioning includes moving the EoAT with a mastthat is coupled to the EoAT wherein the mast includes a mast conveyor;and transferring the cargo item from the EoAT conveyor to the mastconveyor.

Aspect 58 concerns the aspect of any preceding aspect, furthercomprising moving the gripper mechanism from the retracted position toan extended position before said securing; and wherein the grippermechanism is raised above the EoAT conveyor to grip the cargo item whenin the extended position.

Aspect 59 concerns a method, comprising positioning an End of Arm Tool(EoAT), wherein the EoAT has an EoAT conveyor, wherein the grippermechanism includes one or more vacuum cups moving a cargo item with theEoAT conveyor over the gripper mechanism when in a retracted positionextending the gripper mechanism from the retracted position to anextended position where the gripper mechanism is raised above the EoATconveyor to contact the cargo item after said moving the cargo item; andpushing the cargo item off the EoAT conveyor with the gripper mechanismby moving the gripper mechanism along the EoAT.

Aspect 60 concerns the aspect of any preceding aspect, furthercomprising wherein said positioning includes moving the EoAT with a mastthat is coupled to the EoAT wherein the mast includes a mast conveyor;and transferring the cargo item from the mast conveyor to the EoATconveyor.

Aspect 61 concerns the aspect of any preceding aspect, wherein the EoATincludes a guide rail having a front end extending longer than the EoAT,and the front end is spring biased.

Aspect 62 concerns the aspect of any preceding aspect, wherein the EoAThas a vision sensor to sense the cargo item.

Aspect 63 concerns the aspect of any preceding aspect, wherein thepulling includes pulling the cargo item with a second cargo item stackedthereupon.

Aspect 64 concerns the aspect of any preceding aspect, wherein thepushing includes pushing the cargo item with a second cargo item stackedthereupon.

Further forms, objects, features, aspects, benefits, advantages, andembodiments of the present invention will become apparent from adetailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automated unloading and loadingsystem.

FIG. 2 is a rear perspective view of an automated unloading and loadingrobot used in the FIG. 1 system.

FIG. 3 is a front perspective view of the FIG. 2 robot.

FIG. 4 is a top view of the FIG. 2 robot.

FIG. 5 is a bottom view of the FIG. 2 robot with a housing of the FIG. 2robot hidden from view.

FIG. 6 is a front view of the FIG. 2 robot without the housing.

FIG. 7 is a rear view of the FIG. 2 robot without the housing.

FIG. 8 is an enlarged side partial cross-sectional view of the FIG. 2robot.

FIG. 9 is a side view of the FIG. 2 robot without selected components.

FIG. 10 is an enlarged rear perspective view of the FIG. 2 robot shownin FIG. 9.

FIG. 11 is a bottom view of a mast base found in the FIG. 2 robot.

FIG. 12 is an enlarged side view of the FIG. 2 robot shown in FIG. 9.

FIG. 13 is a perspective view of the FIG. 11 mast base and otherassociated components.

FIG. 14 is a rear perspective view of a mast found in the FIG. 2 robot.

FIG. 15 is a top perspective view of the FIG. 14 mast.

FIG. 16 is a top view of the FIG. 14 mast.

FIG. 17 is a side view of the FIG. 14 mast.

FIG. 18 is an enlarged perspective view of an actuator joint joining theFIG. 14 mast to an end of arm tool (EoAT) for the FIG. 2 robot.

FIG. 19 is an enlarged perspective view of the area surrounding the FIG.18 joint.

FIG. 20 is an exploded view of the FIG. 18 joint.

FIG. 21 is a perspective view of the FIG. 18 joint.

FIG. 22 is a front view of the FIG. 18 joint.

FIG. 23 is a top perspective view of FIG. 18 EoAT with a grippermechanism in a retracted position.

FIG. 24 is a top view of the FIG. 18 EoAT with the gripper mechanism inthe retracted position.

FIG. 25 is a front perspective view of the FIG. 18 EoAT with the grippermechanism in an extended position.

FIG. 26 is a top view of the FIG. 18 EoAT with the gripper mechanism inthe extended position.

FIG. 27 is an enlarged top perspective view of a mast facing end of theFIG. 18 EoAT.

FIG. 28 is a side view of a drive track found in the FIG. 18 EoAT.

FIG. 29 is a side view of cam track found in the FIG. 18 EoAT.

FIG. 30 is an enlarged partial perspective view of the FIG. 18 EoAT atthe mast facing end.

FIG. 31 is a front perspective view of the gripper mechanism found inthe FIG. 18 EoAT.

FIG. 32 is a rear perspective view of the FIG. 31 gripper mechanism.

FIG. 33 is a side view of the FIG. 31 gripper mechanism.

FIG. 34 is a top view of the FIG. 31 gripper mechanism.

FIG. 35 is a partial side cross-sectional view of the FIG. 18 EoAT withthe FIG. 31 gripper mechanism in the retracted position.

FIG. 36 is a partial side cross-sectional view of the FIG. 18 EoAT withthe FIG. 31 gripper mechanism in the extended position.

FIG. 37 is an enlarged cross-sectional view of the interface between theFIG. 29 cam track and the FIG. 31 gripper mechanism when in theretracted position.

FIG. 38 is a cross-sectional view of the FIG. 29 cam track and the FIG.31 gripper mechanism when in the extended position.

FIG. 39 is a perspective view of the FIG. 2 robot with a cargo sensorfor detecting cargo items.

FIG. 40 is a top view of the FIG. 18 EoAT before the cargo item isloaded.

FIG. 41 is a top view of the FIG. 18 EoAT when the FIG. 31 grippermechanism is extended to grip the cargo item.

FIG. 42 is a side view of the arrangement shown in FIG. 41.

FIG. 43 is a top view of the FIG. 18 EoAT when the cargo item is loaded.

FIG. 44 is a top view of the FIG. 18 EoAT when the cargo item istraveling across the FIG. 31 gripper mechanism when in the retractedposition.

FIG. 45 is a side view of the arrangement shown in FIG. 44.

FIG. 46 is a block diagram 4600 showing one example of an overallcontrol architecture for the FIG. 2 robot.

FIG. 47 is a perspective view of the FIG. 2 robot during an initialstage of unloading cargo items from a cargo carrier.

FIG. 48 is a perspective view of the FIG. 2 robot during a later stageof unloading the cargo items from the cargo carrier.

FIG. 49 is a partial side cross-sectional view of another alternative ofan automated unloading and loading robot used in the FIG. 1 system.

FIG. 50 is a partial, perspective view of an automated unloading andloading robot that can be used in the FIG. 1 system.

FIG. 51 is a top perspective view of a mast base found in the FIG. 50robot.

FIG. 52 is a bottom perspective view of the FIG. 51 mast base.

FIG. 53 is a perspective view of the frame and mast yaw drive systemfound in the FIG. 50 robot.

FIG. 54 is a partial, perspective view of another automated unloadingand loading robot that can be used in the FIG. 1 system.

FIG. 55 is a side view of the FIG. 54 robot.

FIG. 56 is a top view of the FIG. 54 robot.

FIG. 57 is a bottom view of the FIG. 54 robot.

FIG. 58 is an enlarged top perspective view at an EoAT end of the FIG.54 robot.

FIG. 59 is a top perspective view of an EoAT pitch-yaw actuator jointfound in the FIG. 54 robot.

FIG. 60 is a bottom perspective view of the FIG. 60 EoAT pitch-yawactuator joint.

FIG. 61 is a first partial perspective view of the FIG. 60 EoATpitch-yaw actuator joint.

FIG. 62 is a second partial perspective view of the FIG. 60 EoATpitch-yaw actuator joint.

FIG. 63 is a top perspective view of a pivot block or housing in theFIG. 60 EoAT pitch-yaw actuator joint.

FIG. 64 is a bottom perspective view of the FIG. 63 pivot housing.

FIG. 65 is a partial perspective view of the FIG. 60 EoAT pitch-yawactuator joint when coupled to the EoAT.

FIG. 66 is an enlarged side view of one side of the FIG. 54 robot.

FIG. 67 is an enlarged side view of the opposite side of the FIG. 54robot.

FIG. 68 is a top view of a base unit conveyor in the FIG. 54 robot.

FIG. 69 is an enlarged perspective view of a ball member for a mastconnection joint in the FIG. 68 base unit conveyor.

FIG. 70 is a perspective view of the FIG. 68 base unit conveyor 214 at abase connection joint.

FIG. 71 is a partial perspective view of the FIG. 68 base unit conveyor.

FIG. 72 is a top view of another example of an EoAT.

DESCRIPTION OF THE SELECTED EMBODIMENTS

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates. One embodiment of the invention is shown in great detail,although it will be apparent to those skilled in the relevant art thatsome features that are not relevant to the present invention may not beshown for the sake of clarity.

The reference numerals in the following description have been organizedto aid the reader in quickly identifying the drawings where variouscomponents are first shown. In particular, the drawing in which anelement first appears is typically indicated by the left-most digit(s)in the corresponding reference number. For example, an elementidentified by a “100” series reference numeral will likely first appearin FIG. 1, an element identified by a “200” series reference numeralwill likely first appear in FIG. 2, and so on.

FIG. 1 shows a perspective view of an automated unloading and loadingsystem 100 according to one example. The system 100 includes anautomated unloading and loading robot 102 and an extendable conveyorsystem 104 operatively positioned between the robot 102 and a mainconveyor system 106, which is typically (but not always) found in awarehouse and/or manufacturing plant. As shown, the robot 102 isconfigured to move in and out of a cargo carrier 108, such as asemi-trailer or flatbed trailer, in a progressive manner. Alternativelyor additionally, the robot 102 is able to move between various dockdoors as well as other cargo carriers 108. As the robot 102progressively moves in and out of the cargo carrier 108, the extendableconveyor system 104 extends or retracts, depending on the movement ofthe robot 102 in the cargo carrier 108 as well as elsewhere. Theextendable conveyor system 104 can for example include connectors,cabling, and/or tubing for supplying electrical power, air, and/orcommunication pathways to the robot 102. The robot 102 is configured toload and/or unload cargo items 110 from the cargo carrier 108. In theillustrated example, the cargo items 110 are in the form of boxes, butin other examples, other types of cargo items 110, such as bags, drums,cases, etc., can be loaded and/or unloaded from the cargo carrier 108with the robot 102. As will be explained in greater detail below, therobot 102 is configured to load and/or unload the cargo items 110 withinthe cargo carrier 108 in a continuous or near continuous fashion. As aresult, the robot 102 is able to quickly service the cargo carrier 108.The robot 102 is designed to rapidly stack and unstack the cargo items110 within the cargo carrier 108 as well as unstack or unload the cargoitems 110 from the cargo carrier 108 with minimal movement.Consequently, the cargo carrier 108 can be rapidly loaded and unloadedautomatically without any (or minimal) human interaction. As can be alsoseen in FIG. 1, the robot 102 is able to pack or unpack the cargo items110 from the bottom and nearly to the top and sides of the cargo carrier108 so as to efficiently almost fill the entire space inside the cargocarrier 108, if needed.

To provide some context, the system 100 will be described with referenceto a warehousing environment, but it should be recognized that thesystem 100 can be used in other types of environments, such asmanufacturing plants, food processing plants, and/or agriculturalenvironments, to name just a few examples. Besides on or inside thecargo carrier 108, the robot 102 can be used to stack or unstack cargoitems 110 at other locations, such as at various storage or staginglocations within a building 112. As illustrated, the extendable conveyorsystem 104 and the main conveyor system 106 are typically located withinthe building 112, such as a warehouse. The extendable conveyor system104 transports the cargo items 110 between the robot 102 and the mainconveyor system 106, and vice versa. The main conveyor system 106 forinstance can supply the cargo items 110 to various processing equipmentand/or storage locations within the building 112. The robot 102 is ableto service the cargo carrier 108 through a standard loading dock 114 inthe building 112 such that no modifications to the loading dock 114and/or building 112 are typically required.

FIGS. 2 and 3 respectively show rear and front perspective views of therobot 102, and FIG. 4 shows a top view of the robot 102. As can be seen,the robot 102 includes a base unit 202, a mast 204 extending from thebase unit 202, and an end of arm tool (EoAT) 206 extending from the mast204. To move and manipulate the EoAT 206, the robot 102 has a series ofjoints (i.e., J1, J2, J3, J4, and J5) that provide a number of degreesof freedom of movement. The base unit 202 is generally configured toprovide power, move, and control the general operation of the robot 102.The mast 204 is designed to position the EoAT 206 as well as provide apathway for conveying the cargo items 110 between the base unit 202 andthe EoAT 206. The EoAT 206 is configured to rapidly stack and unstackthe cargo items 110 in the cargo carrier 108. The EoAT 206 has a lowprofile to make picking or placing cargo items 110 from the floor of thecargo carrier 108 or building 112 easier as well as in stacks of cargoitems 110. The EoAT 206 is shaped so that the cargo item 110 only needsto be lifted 2 to 3 inches (about 5-8 cm) from the floor to be placed onthe EoAT 206, but in other examples, the cargo items 110 can be liftedto lower or higher heights from the floor. For instance, the EoAT 206 inother examples can include a heavy duty version that is larger forlifting larger and/or heavier cargo items 110. This also allows cargoitems 110 to be packed close to the top of the cargo carrier 108. In oneexample, the cargo items 110 only leave a 7 inch (about 18 cm) empty gapat the top of the cargo carrier 108. The robot 102 is configured to loadand unload the cargo items 110 using a serpentine pattern at a highrate. In one form, the robot 102 is able to stack or unstack the cargoitems 110 at an average rate of no more than one (1) cargo item 110 perevery three (3) seconds.

As shown, the base unit 202 includes a transport system 208 that isconfigured to move the robot 102. The base unit 202 along with the restof the robot 102 can be powered in any number of manners. In theillustrated example, the robot 102 is electrically powered by anexternal power source (e.g., power cable with a plug), but in otherexamples, the robot 102 can be self-powered and/or powered in otherways, such as through batteries, solar cells, pneumatically throughpneumatic tanks, hydraulically through hydraulic lines, and the like.The base unit 202 further has one or more controllers 210 forcontrolling the operation of the robot 102 along with a mast actuatorsystem 212 that is configured to move the mast 204. In one form, thecontrollers 210 include Programmable Logic Controllers (PLCs). The baseunit 202 can include other components to enhance safety, such aslighting, safety scanners, as well as safety electronic (E) stopradiofrequency (RF) receivers. The base unit 202 also serves as aweighted counter balance to counterbalance the weight of the mast 204and EoAT 206 as well any cargo items 110 thereon.

A base unit conveyor 214, which is located on the top of the base unit202, conveys the cargo items 110 between the mast 204 and the extendableconveyor system 104. In the illustrated example, the base unit conveyor214 includes a mast section 216 and a transition section 218 that arenested together so as to overlap. This overlap between the mast section216 and the transition section 218 is able to compensate for therelative changes of distance between the end of the mast 204 and the endof the extendable conveyor 104 as the mast 204 moves. In the depictedexample, the mast section 216 includes a pair of belt conveyors 220, andlikewise, the transition section 218 includes a pair of belt conveyors222. Looped ends of each of belts 220 of the mast section 216 aresecured to the mast 204, and looped ends of the belts 220 for thetransition section 218 are secured to the base unit 202. In theillustrated example, the belt conveyors 222 of the transition section218 are positioned in between the belt conveyors 220 of the mast section216, but in other examples, the respective positions of the beltconveyors 220, 222 can be reversed. This configuration provides stablesupport as the cargo items 110 transition between the mast 204 and theextendable conveyor system 104. The base unit 202 further includes abase unit housing 224 that covers and protects the various components ofthe base unit 202. A vent tube 226 extending from one of the controllers210 circulates air for cooling the controllers 210. The base unit 202further includes one or more safety scanners or sensors 228 that sensesobjects, individuals, and/or structures located around the robot 102. Inone example, the safety scanners 228 are in the form of light curtainsfor sensing the relative location of the robot 102. For instance, thesafety scanners 228 can sense when personnel get too close to the robot102 such that operation of the robot 102 can cease or enter a safeoperational mode. The safety scanners 228 can also sense the walls ofthe cargo carrier 108 so that the robot 102 is properly positionedwithin the cargo carrier 108.

Cargo containers 108 typically provide limited space in which the robot102 is able to maneuver. The transport system 208 is configured toenhance the mobility of the base unit 202 so that the robot 102 is ableto maneuver within the tight confines of cargo containers 108. FIG. 5shows a bottom view of the robot with the base unit housing 224 removed.As can be seen, the transport system 208 includes a chassis or frame 502and wheels 504 rotatably mounted to the frame 502. In the illustratedexample, the transport system 208 includes four wheels 504, but in otherexamples, the transport system 208 can include more or less wheels 504.It is envisioned that other mechanisms for moving, such as magneticlevitation, pneumatic systems, and the like, can be used instead ofwheels 504. As indicated by the double arrows, the wheels 504 are ableto rotate or pivot to a great degree relative to the frame 502 in orderto enhance mobility of the robot 102. In one form, the wheels 504 areable to pivot to at least ninety-degree (90°) angles (perpendicular)relative to the longitudinal axis 506 of the robot 102, and in othervariations, the wheels 504 have three-hundred-sixty (360°) mobility.

FIGS. 6 and 7 respectively illustrate front and back views of the robot102 with selected components, such as the base unit housing 224, removedto enhance visibility. As can be seen, each wheel 504 has a wheelbracket 602 pivotally mounted to the frame 502 to facilitate steering ofthe robot 102. Each wheel 504 in the illustrated example furtherincludes a wheel motor 604 that is mounted to the wheel bracket 602 inorder to drive the wheels 504. In one form, the wheel motor 604 is anelectric motor, but in other examples, other types of motors, such aspneumatic and hydraulic type motors, can be used. Moreover, one or moreof the wheels 504 can be unpowered such that the wheel 504 does notinclude the wheel motor 604. Referring now to FIGS. 7 and 8, the wheelbrackets 602 are rotated relative to the frame 502 via a steeringmechanism 702. In the illustrated example, the steering mechanism 702includes one or more steering chains 704 looped around and engagingwheel bracket gears 706 and steering gear 708 in order to steer thewheels 504. In other examples, other types of structures can control thesteering, such as rack-pinion designs and steering belts. Looking atFIG. 8, a steering motor 802, such as an electric and/or pneumaticmotor, drives the steering gears 708. In one form, the shaft of thesteering motor 802 is connected to the steering gears 708 directly, butin other forms, a gearbox or transmission can be used to indirectlycouple the steering motor 802 to the steering gears 708. The robot 102in one example can include a single steering motor 802 that controls allof the wheels 504, and in the illustrated example, the robot 102includes a steering motor 802 at each end so as to separately controlthe front and back wheels 504. In other variations, each wheel 504 canbe independently steered and controlled. Once more, this overall designof the transport system 208 allows the robot 102 to make extremely tightturns.

Turning to FIG. 9, which shows a side view of the robot 102 withselected components removed to aid visibility, the mast actuator system212 is configured to control the yaw (i.e., horizontal, or side-to-side)and pitch (i.e., vertical, or up and down tilt) orientations of the mast204 along with the EoAT 206. Specifically, the mast actuator system 212can be subdivided into a mast yaw control subsystem 902 that controlsthe yaw of the mast 204 (e.g., acts as a J1 joint) and a mast pitchcontrol subsystem 904 that controls the pitch of the mast 204 as well asthe extension and retraction of the mast 204 along the longitudinal axis506 (J2 and J3 joints). The mast yaw control subsystem 902 includes amast base 906 that is rotatably mounted to the frame 502 and a mast yawdrive 908 that is configured to rotate the mast base 906 relative to theframe 502. As can be seen, the mast base 906 supports the mast 204 andthe components of the mast pitch control subsystem 904. Looking at FIGS.10 and 11, the mast yaw drive 908 includes a mast yaw drive motor 1002with a mast yaw drive gearbox 1004 that is mounted to the frame 502. Themast yaw drive gearbox 1004 has a pinion gear 1006 that engages a rack1008 attached to the mast base 906. As depicted, the rack 1008 has asemicircular shape so as to facilitate rotation of the mast base 906.The mast yaw drive motor 1002 in one example is a reversible motor sothat the pinion gear 1006 can be rotated in opposite directions. This inturn allows the mast 204 to be rotated in clockwise and counterclockwisedirections. To facilitate smooth rotation, the mast base 906 has abearing or slew ring 1010 mounted to a bearing block 1012 on the frame502. The bearing ring 1010 includes bearings to reduce friction betweenthe mast base 906 and the bearing block 1012. It should be recognizedthat other friction reducing structures or techniques, such aslubricants, special materials, magnetic bearings, and the like, can bealternatively or additionally used to reduce friction.

Turning to FIGS. 12 and 13, the mast pitch-extension control subsystem904 in the mast actuator system 212 include a series of linkages 1202that connect the mast 204 to the mast base 906. The height of the mast204 (relative to the floor) at a neutral, level position is set so thatthe EoAT 206 is positioned at or near the middle of an average stackheight of cargo items 110 in the cargo carrier 108. Having the EoAT 206centered in the middle location reduces the overall travel time anddistance for the mast 204 and EoAT 206 as well as reduces cantileveredloading on the base unit 202. With the mast 204 mast being relativelylong and being normally positioned in the middle of the stack, the masthas a maximum incline or pitch angle of at most 25 degrees (25°) and amaximum yaw (side-to-side) angle of at most 20 degrees (20°). Thisconfiguration provides a gradual slope and transition for the cargoitems 110 being transported on the mast 204 and EoAT 206 which in turnreduces the risk of jamming and/or cargo items 110 from falling off therobot 102, even when the mast 204 and/or EoAT 206 is moved.

In the illustrated example, the mast pitch-extension control subsystem904 includes a pair of rocker mechanisms for moving the mast 204. Therocker mechanisms are formed by the linkages 1202, and these linkages1202 in part include a mast extension arm 1204 that is pivotallyconnected to the mast base 906 at one end via an extension arm coupling(or bearings) 1206 and pivotally connected to the mast 204 at the otherend. As can be seen, the extension arm coupling 1206 is centered overthe bearing ring 1010 so as to reduce the torque required to rotate themast 204. In particular, the pivot point for the extension arm 1204 iscentered over the bearing ring 1010 to reduce the movement of the end ofthe mast 204. This can also reduce the moment load on the bearing ring1010 and reduce the torque required to rotate the mast 204. Pivotalmovement of the mast extension arm 1204 causes the mast 204 along withthe EoAT 206 to move horizontally in the longitudinal direction 506 ofthe robot 102. In other words, pivoting of the mast extension arm 1204causes the EoAT 206 to extend or retract while the base unit 202 remainsstationary, if so desired. To facilitate this, the mast actuator system212 includes an extension drive 1208 with an extension crank 1210 thatis connected to the mast extension arm 1204 via an extension link 1212.As the extension drive 1208 rotates the extension crank 1210, the mastextension arm 1204 pivots about the extension arm coupling 1206. Forinstance, when the extension crank 1210 is rotated in thecounterclockwise direction (as viewed in FIG. 12), the mast 204 isretracted which in turn retracts the EoAT 206. Conversely, when theextension drive 1208 rotates the extension crank 1210 in a clockwisedirection, the EoAT 206 is extended in the longitudinal direction 506.

This ability to extend and retract the mast 204 in the longitudinaldirection 506 allows the base unit 202 to remain generally stationary asthe pitch and/or the yaw of the mast 204 is changed. If leftuncompensated, the EoAT 206 would not be able to reach all of the cargoitems 110 within a row or stack of the cargo items 110 because ofarc-shaped pivoting movement of the EoAT 206. By being able to extendand retract the EoAT 206 with the mast 204, the mast extension arm 1204ensures that the EoAT 206 is properly positioned to stack and/or unstackthe cargo items 110 when the pitch and/or yaw of the mast 204 is changedby the mast actuator system 212. In certain situations, the robot 102 isable to stack or unstack multiple rows of cargo items 110 without havingto move the base unit 202 with the transport system 208.

With continued reference to FIGS. 12 and 13, a mast pitch arm 1214 isused to control the pitch or vertical movement of the mast 204. A pitchdrive 1216 is operatively connected to the mast pitch arm 1214 via apitch crank 1218. As shown, the pitch crank 1218 has a bent, hockeystick shape. The pitch drive 1216 is able to control the pitch of themast 204 via the pitch crank 1218 and mast pitch arm 1214. This in turnallows the pitch drive 1216 to control the vertical location of the EoAT206. In the illustrated example, as the pitch crank 1218 is moved in acounterclockwise direction (as viewed in FIG. 12), the mast 204 ispitched in an upwards direction such that the EoAT 206 moves upwards.When the pitch crank 1218 is moved in a clockwise direction, the mast204 is pitched in a downwards direction such that the EoAT movesdownwards. As noted before, the extension drive 1208 via the mastextension arm 1204 typically, but not always, works in conjunction withthe pitch drive 1216 to ensure that the EoAT 206 is properly positionedso as to still be able to engage with the cargo items 110 as the pitchof the mast 204 changes. To reduce the cantilevered loading of the mast204 on the pitch drive 1216, the mast actuator system 212 includes amast counterbalance system 1220. In one form, the mast counterbalancesystem 1220 includes one or more air springs 1222 that are coupledbetween the mast 204 and the mast base 906. As shown, the mast base 906includes an air spring connector 1224 to which the air spring 1222 ispivotally connected. In the illustrated example, the mast counterbalancesystem 1220 includes a pair of the air springs 1222, but more or lesscan be used in other examples. Moreover, other types of counterbalancesystems 1220 can be used. For example, as will be explained below withreference to FIG. 49, a counterweight can be used to help balance orcompensate for the weight of the mast 204 as well as the EoAT 206 andany cargo items 110 thereon.

Turning to FIG. 13, the mast base 906 defines a crank notch 1302 inorder to provide a clearance for the pitch crank 1218. The extensiondrive 1208 and the pitch drive 1216 respectively include extension 1304and pitch 1306 drive motors with gearboxes 1308, 1310. In theillustrated example, the drive motors 1304, 1306 are electric motors,but it should be appreciated that other types of motors, such aspneumatic and/or hydraulic motors, can be used. Moreover, it should berecognized that the mast pitch-extension control subsystem 904 can beconfigured differently in other examples. For example, hydraulic and/orpneumatic pistons can be used to position the mast 204.

FIG. 14 shows a rear perspective view of the mast 204. As shown, themast 204 includes a mast support arm 1402, a mast conveyor 1404, one ormore guide rails 1406, and a mast arm cover 1408. The mast support arm1402 provide structural support for the components of the mast 204 aswell as provides a structural connection between the base unit 202 andEoAT 206. The mast conveyor 1404 is configured to convey the cargo items110 between the base unit 202 and EoAT 206. In the illustrated example,the mast 204 includes a pair of guide rails 1406 that are positioned onopposite sides of the mast conveyor 1404 to prevent the cargo items 110from accidentally falling off of the mast 204 when transported.

FIG. 15 shows a front perspective view of the mast with the mast armcover 1408 removed. As depicted, the mast support arm 1402 defines amast channel 1502 that is covered by the mast arm cover 1408. In oneexample, the mast arm cover 1408 is made of Ultra-high-molecular-weightpolyethylene (UHMW), but the mast arm cover 1408 in other examples canbe made of different materials. The mast arm cover 1408 preventscontaminants or other items from falling into the mast channel 1502which in turn protects components contained within the mast channel1502. The mast support arm 1402 has generally a U-shaped (or hat-shaped)cross-sectional shape. In one form, the mast support arm 1402 is analuminum 6061 T6 hat channel type structural support such that the mast204 is lightweight, but the mast support arm 1402 can be different inother examples. In addition to the components of the mast 204 housedinside the mast channel 1502 of the mast support arm 1402, the mastchannel 1502 provides a conduit for housing power cabling, communicationlines, air hosing, wiring, and other components for the EoAT 206.

Referring now to FIGS. 16 and 17, the mast conveyor 1404 in theillustrated example includes a pair of belt conveyors 1602 in order tominimize weight, but it should be recognized that other types ofconveyors can be used. Both belt conveyors 1602 are powered by aconveyor drive 1604 via conveyor drive pulley 1606. In the illustratedexample, the conveyor drive 1604 includes a motor 1608, such as anelectric motor or pneumatic motor, that is coupled to a gearbox 1610that drives the conveyor drive pulleys 1606 on opposing sides of themast support arm 1402. As can be seen, the conveyor drive 1604 ispositioned closer to the base unit 202 as compared to the EoAT 206.Having the conveyor drive 1604, which is relatively heavy, positionedcloser to the base unit 202 reduces the torque and resulting energyrequired to move the mast 204. As can be seen, the mast support arm 1402is also tapered closer to the EoAT 206 so as to minimize weight closerto the EoAT 206 which in turn reduces the amount of power needed to movethe mast 204. In other words, the design of the mast 204 significantlyreduces the cantilevered loads of the robot 102 which in turn improvescycle time during use.

The mast channel 1502 at the end of the mast 204 near the EoAT 206 alsohouses an EoAT pitch or tilt drive 1612. The EoAT pitch drive 1612 isdesigned to control the pitch or tilt of the EoAT 206 relative to themast 204. As shown, the EoAT pitch drive 1612 includes an EoAT pitchmotor 1614 that is connected to an EoAT pitch gearbox 1616. Drivepulleys or sprockets 1618, which are connected to the driveshafts of theEoAT pitch gearbox 1616, are positioned on opposite sides of the mastsupport arm 1402 and are configured to power EoAT pitch drive belts1620. In one form, the EoAT pitch motor 1614 includes a reversible motorso that the EoAT pitch drive belts are able to move in both directionsto facilitate pitching of the EoAT 206 in either direction. It iscontemplated that transmissions or other similar devices can be used toachieve the same result.

Turning to FIG. 18, an EoAT pitch-yaw actuator joint 1802 connects themast 204 to the EoAT 206. The EoAT pitch-yaw actuator joint 1802 isconfigured to move the EoAT 206 in a pitch direction as indicated bydouble arrow 1804 and a yaw direction as indicated by arrows 1806. Inother words, the EoAT pitch-yaw actuator joint 1802 acts as two joints,that is, the J4 and J5 joints for the robot 102. The EoAT pitch drive1612 via the EoAT pitch drive belts 1620 moves EoAT 206 in the pitchdirection 1804 (e.g., up and down) via the EoAT pitch-yaw actuator joint1802. Looking at FIG. 19, the mast channel 1502 in the mast support arm1402 houses an EoAT yaw drive 1902 that is configured to move the EoAT206 in the yaw direction 1806 (e.g., side-to-side). The EoAT yaw drive1902 includes an EoAT yaw motor (and/or gearbox) 1904, such as in theform of an electric or pneumatic motor, that powers a yaw drive belt1906 via a drive gear or pulley 1908. The yaw drive belt 1906 in turnpowers the EoAT pitch-yaw actuator joint 1802 to move the EoAT 206 inthe yaw direction 1806. In one form, the EoAT yaw motor 1904 is areversible type motor such that the belt 1906 can move in bothdirections so as to move the EoAT 206 in both yaw directions 1806. Inother examples, a transmission or other similar device can be used toachieve the same result.

FIGS. 20, 21, and 22 respectively show exploded, enlarged perspective,and front end views of the EoAT pitch-yaw actuator joint 1802. As shown,the EoAT pitch-yaw actuator joint 1802 includes an EoAT bracket 2002that is configured to mount to the end of the EoAT 206. The EoAT bracket2002 has a pair of opposing bracket flanges 2004 that define a bracketcavity 2006. The bracket flanges 2004 each define a yaw pivot pinopening or shaft channel 2008 in which a yaw pivot pin or shaft 2010 isreceived. A yaw rack gear 2012 is mounted at a fixed position to one ofthe bracket flanges 2004. In one example, the yaw rack gear 2012 isbolted to the bracket flanges 2004, but in other examples, the yaw rackgear 2012 can be secured at a fixed position on the bracket flange 2004in other ways, such as via keying, welding, adhesives, etc. A pivotblock 2014 is received in the bracket cavity 2006 between the bracketflanges 2004. The pivot block 2014 defines a pin or shaft opening 2016through which the yaw pivot pin 2010 extends. At opposite ends of thepin opening 2016, the pivot block 2014 defines bearing cavity 2018 inwhich yaw bearing assemblies 2020 are received. The yaw bearingassemblies 2020 are received around the yaw pivot pin 2010 so as toreduce friction between the pivot block 2014 and the yaw pivot pin 2010.This in turn allows the pivot block 2014 to freely rotate about the yawpivot pin 2010. At one end, the pivot block 2014 has a gear clearancemember 2022 that is received in a yaw rack gear opening 2024 in the yawrack gear 2012. This configuration allows the yaw rack gear 2012 tofreely rotate around the pivot block 2014. When the yaw rack gear 2012is driven, the EoAT bracket 2002 is able to rotate about the yaw pivotpin 2010 in the yaw direction 1806. The gear clearance member 2022 inthe illustrated example is in the form of a cut back in the pivot block2014, but clearance member 2022 can be configured differently in otherexamples.

On opposing sides, the pivot block 2014 further defines pitch driveshaftopenings 2026 in which pitch driveshafts 2028 are secured in a fixedmanner. In one example, the pitch driveshafts 2028 are welded in thepitch driveshaft openings 2026 of the pivot block 2014, but the pitchdriveshaft 2028 can be secured to the pivot block 2014 in other manners.For instance, the pitch driveshafts 2028 can be integrally formed withthe pivot block 2014. When the pitch driveshafts 2028 are rotated, thepivot block 2014 is likewise rotated which in turn causes the EoAT 206to pitch or tilt in the pitch direction 1804. At the end opposite thepivot block 2014, the pitch driveshafts 2028 each have a pitch drivepulley 2030 with a pitch drive keyless bushing 2032 securing the pitchdrive pulley 2030 to the pitch driveshaft 2028. The pitch drive pulleys2030 are secured to the pitch driveshafts 2028 in a fixed manner (e.g.,keyed) so that, as the pitch drive pulleys 2030 are rotated, the pitchdriveshafts 2028 are able to rotate the pivot block 2014. It should berecognized that the pitch drive pulleys 2030 can be secured in otherways besides through the pitch drive keyless bushing 2032. For example,the pitch drive pulleys 2030 can be welded or integrally formed with thepitch driveshafts 2028 and/or keyed to a keyed bushing. Although twopitch drive pulleys 2030 are shown, it should be recognized that asingle pitch drive pulley 2030 can be used or more than two pitch drivepulleys 2030 can be used. As shown, the pitch driveshafts 2028 extendthrough shaft bearing guides 2034 that facilitate smooth rotation of thepitch driveshafts 2028. The shaft bearing guides 2034 are secured to thewalls of the mast support arm 1402 that are located on opposite sides ofthe mast channel 1502.

A yaw drive gear 2036 is coupled to a yaw pinion gear 2038 in a fixedmanner (e.g., keyed). Both the yaw drive gear 2036 and the yaw piniongear 2038 are rotatably coupled to one of the pitch driveshafts 2028 viaa yaw bearing assembly 2040. With the yaw bearing assembly 2040, the yawdrive gear 2036 and the yaw pinion gear 2038 are able to rotate freelyabout the pitch driveshaft 2028. The teeth of the yaw pinion gear 2038engage the teeth of the yaw rack gear 2012 in a bevel gear typearrangement. In the illustrated example, the yaw rack gear 2012 and theyaw pinion gear 2038 are in a bevel gear type arrangement, but thesegears 2012, 2038 can be arranged differently in other examples. As theyaw drive gear 2036 is rotated, the yaw pinion gear 2038 causes the EoATbracket 2002 to rotate in the yaw direction 1806 which in turn causesthe EoAT 206 to move in a similar fashion.

Operation of the EoAT pitch-yaw actuator joint 1802 will now bedescribed with reference to FIGS. 18-22. To move the EoAT 206 in thepitch direction 1804, the EoAT pitch drive 1612 drives the EoAT pitchdrive belts 1620 which in turn drives the pitch drive pulleys 2030. Asthe pitch drive pulleys 2030 rotate, the pitch driveshaft 2028 cause thepivot block 2014 to pitch or pivot. The pitching of the pivot block 2014causes the EoAT bracket 2002 to likewise pivot, thereby causing the EoAT206 to pitch (i.e., tilt in the vertical direction). When the EoAT pitchdrive 1612 drives the EoAT pitch drive belts 1620 in an oppositedirection, the EoAT 206 pitches in the opposite pitch direction 1804. Tomove the EoAT 206 in the yaw direction 1806, the EoAT yaw drive 1902drives the EoAT yaw drive belt 1906 which in turn drives the yaw drivegear 2036. Driving of the yaw drive gear 2036 causes the yaw pinion gear2038 to rotate about the pitch driveshaft 2028. Rotation of the yawpinion gear 2038 causes the yaw rack gear 2012 to rotate the EoATbracket 2002. This in turn causes the EoAT 206 to move in the yawdirection 1806. When the EoAT yaw drive 1902 drives the EoAT yaw drivebelt 1906 in the opposite direction, the EoAT 206 moves in the oppositeyaw direction 1806.

FIGS. 23 and 24 respectively illustrate front perspective and top viewsof the EoAT 206 with a gripper mechanism 2302 in a retracted position.FIGS. 25 and 26 respectively depict front perspective and top views ofthe EoAT 206 with the gripper mechanism 2302 in an extended position.The gripper mechanism 2302 is designed to grab the cargo items 110 andpull them onto the EoAT 206 when unloading the cargo items 110 from thecargo carrier 108 or elsewhere. The gripper mechanism 2302 is alsoconfigured to push or direct the cargo items 110 off of the EoAT 206when loading or stacking the cargo items 110 in the cargo carrier 108 orelsewhere. The EoAT 206 further includes a conveyor system 2304 that isconstructed to convey or move the cargo items 110 along the EoAT 206.The conveyor system 2304 facilitates loading and unloading cargo items110 in a continuous or near continuous fashion. During unloading of thecargo items 110 from the cargo carrier 108, once the gripper mechanism2302 pulls the cargo item 110 onto the conveyor system 2304, theconveyor system 2304 moves the cargo item 110 towards the mast 204 sothat the cargo item 110 can be transferred to the mast conveyor 1404.When loading or stacking the cargo items 110 into the cargo carrier 108,the conveyor system 2304 moves the cargo items 110 from the mast 204towards the end of the EoAT 206. As shown, the EoAT 206 further includesa pair of opposing guide rails 2306 that among other things prevent thecargo items 110 from falling off of the EoAT 206. The guide rails have aflared or hourglass shape which helps to direct cargo items 110 evenwhen the cargo items are skewed on the conveyor system 2304. The flaringof the guide rails 2306 facing the mast 204 helps also withtransitioning the cargo items 110 between the EoAT 206 and the mast 204when the EoAT 206 is not directly aligned with the mast 204 (e.g., theEoAT 206 is at a yaw angle that is transverse to the mast 204). Inessence, the guide rails 1406 on the mast 204 and the guide rails 2306on the EoAT 206 form a dual-sided funnel so that any skewed cargo items110 are properly aligned as the cargo items 110 travel on the robot 102.In one form, the guide rails 1406, 2306 are made of flexible steel,specifically spring steel, to allow for example the guide rails 1406,2306 to flex when pressed against any walls, such as in the cargocarrier 108, and to spring back to its original shape afterwards.

Normally, but not always, the gripper mechanism 2302 is positioned inthe retracted position as is depicted in FIGS. 23 and 24. When thegripper mechanism 2302 is in the retracted position, the grippermechanism 2302 is positioned below the top surface of the conveyor beltsfor the conveyor system 2304 so that the cargo items 110 are able to betransported on the conveyor system 2304. In addition, the grippermechanism 2302 is positioned in the retracted position sometimes duringmovement of the EoAT 206 so as to reduce cantilevered loading of theEoAT 206 which in turn improves the overall movement and speed of therobot 102. As can be seen, when in the retracted position, the grippermechanism 2302 is positioned closer to the mast 204 so as to reduce thecantilevered loading. To grab or discharge a cargo item 110 from theEoAT 206, the gripper mechanism 2302 moves from the retracted positionto the extended position, as is depicted in FIGS. 25 and 26. Looking atFIGS. 23 and 25, the EoAT 206 includes one or more drive tracks 2308with guide slots 2310 for guiding the linear movement of the grippermechanism 2302 between the extended and retracted positions. In theillustrated example, the EoAT 206 includes a pair of the drive tracks2308 that forms part of the structural support or frame of the EoAT 206.In other examples, the EoAT 206 can include a single drive track 2308 ormore than two drive tracks 2308. The EoAT 206 further includes one ormore cam tracks 2312 with cam surfaces 2314 for guiding the verticalmovement of a gripping or engagement section 2316 of the grippermechanism 2302 as the gripper mechanism 2302 moves between the retractedand extended positions. In essence, the cam tracks 2312 in conjunctionwith the gripper mechanism 2302 form a linear cam for guiding thevertical movement profile of the gripping section 2316. As can be seen,the EoAT 206 has a mast facing end 2318 where the EoAT 206 is connectedto the mast 204. Opposite the mast facing end 2318, the EoAT 206 has acargo facing end 2320 where the cargo items 110 are loaded onto orunloaded from the EoAT 206. The gripper mechanism 2302 is positioned atthe cargo facing end 2320 when in the extended position and is movedtowards the mast facing end 2318 during retraction. In the illustratedexample, the drive tracks 2308 and the cam tracks 2312 are illustratedas being separate components, but in other examples, the functionalityof the drive tracks 2308 and cam tracks 2312 can be integrated togetherto form a single unit or track.

As will be explained in greater detail below, the gripping section 2316is designed to grab the cargo item 110 and pull the cargo item 110 ontothe conveyor system 2304. To accomplish this, the gripping section 2316is raised above the conveyor system 2304 so that the gripping section2316 is able to engage and pull the cargo item 110 fully onto theconveyor system 2304. To push the cargo items 110 from the conveyorsystem 2304, the gripping section 2316 is also raised. The cam surfaces2314 on the cam tracks 2312 are contoured to adjust the vertical profileof the gripping section 2316 of the gripping mechanism 2302 duringextension and retraction so that the gripping section 2316 can be raisedabove and lowered below the conveyor system 2304 at the appropriatetime.

To sense whether or not cargo items 110 are on the EoAT 206 as well asthe relative position of the cargo items 110, the EoAT 206 includes acargo sensor system 2322. In the illustrated example, the cargo sensorsystem 2322 is positioned between the cam tracks 2312 near the cargofacing end 2320, but the cargo sensor system 2322 can be positionedelsewhere in other examples. The cargo sensor system 2322 in thedepicted example includes a mast facing sensor 2324 that senses thepresence and/or position of the cargo items 110 near the mast facing end2318 and a cargo facing sensor 2326 that senses the presence and/orposition of the cargo items near the cargo facing end 2320. In one formthe sensors 2324, 2326 are photo-eye type sensors, but it should beappreciated that other types of sensors, such as proximity sensors,light curtains, lasers, and/or cameras, can be used. At the cargo facingend 2320, the EoAT 206 further includes a guide roller 2328 that is ableto roll so as to assist in loading and unloading the cargo items 110from the EoAT 206.

FIG. 27 shows an enlarged perspective view of the mast facing end 2318of the EoAT 206 with several components removed to enhance thevisibility of a portion of the conveyor system 2304. In the illustratedexample, the conveyor system 2304 is a belt type conveyor system inorder to conserve weight of the EoAT 206. The conveyor system 2304includes a conveyor drive 2702 in the form of a servomotor that drives aconveyor driveshaft 2704 via a drive belt 2706. Drive wheels 2708 arepositioned on opposite ends of the conveyor driveshaft 2704, and thedrive wheels 2708 each drive conveyor belts 2710 that extend alongopposite sides of the EoAT 206. In the depicted example, the conveyordrive 2702, which is relatively heavy, is positioned at the mast facingend 2318 in order to reduce the cantilevered loads on the EoAT pitch-yawactuator joint 1802. It is envisioned that other types of conveyorsystems, besides the one illustrated, can be used in other variations.

FIG. 28 illustrates a side view of one of the drive tracks 2308. As canbe seen, the drive track 2308 generally tapers from the mast facing end2318 to the cargo facing end 2320. This tapering reduces cantileveredloading on the EoAT 206 and further allows the cargo facing end 2320 ofthe EoAT 206 to get as close to the floor of the cargo carrier 108 aspossible to reduce the required lifting distance for pulling the cargoitems 110 onto the EoAT 206. Again, the drive track 2308 defines theguide slot 2310 that is used to guide the gripper mechanism 2302 whenmoving between the extended and retracted positions. To further reduceweight, the drive track 2308 includes trussed sections 2802 that definetruss or cut-out openings 2804.

FIG. 29 depicts a side view of one of the cam tracks 2312. The cam track2312 generally tapers from the mast facing end 2318 to the cargo facingend 2320. The cam track 2312 is tapered to provide a motion profile forloading the cargo items 110 onto the EoAT 206 that generally coincideswith the tapered profile of the EoAT 206. The cam track 2312 has trussedsections 2902 defining truss or cut-out openings 2904. As noted before,the cam track 2312 acts like a linear cam for the gripper mechanism2302. The cam surface 2314 has various sections or contours that controlthe vertical movement of the gripping section 2316 of the grippermechanism 2302. Starting from the mast facing end 2318, the cam surface2314 includes a retracted section 2906 where the gripping section 2316of the gripper mechanism 2302 is at or below the top of the conveyorbelts 2710 so that the cargo items 110 are unobstructed and can readilytravel over the gripper mechanism 2302 when in the retracted position.As shown, the cam surface 2314 further has a transition section 2908where the gripping section 2316 is either raised or lowered, dependingon the direction the gripper mechanism 2302 is traveling. The transitionsection 2908 provides a transition between the retracted section 2906and an engagement section 2910 which is relatively higher than theretracted section 2906. Along the engagement section 2910, the grippingsection 2316 is raised above the top of the conveyor system 2304 so thatthe gripping section 2316 of the gripper mechanism 2302 is able toengage with the cargo item 110. The engagement section 2910 is generallycontoured to coincide with the height of the conveyor system 2304 sothat the gripping section 2316 remains above the conveyor system 2304.At the cargo facing end 2320, the profile of the cam surfaces 2314 islowered at an extended section 2912 where the gripping section 2316 ofthe gripper mechanism 2302 extends. The extended section 2912 lowers thegripping section 2316 so that the EoAT 206 is able to reach cargo items110 at lower locations. In particular, this profile gives the grippermechanism 2302 enough vertical travel so as to be able to pick the cargoitems 110 off of the floor. Moreover, with the gripping section 2316being lower, the gripper mechanism 2302 tends to grip the lower sectionof the cargo item 110 which in turn enhances stability whentransitioning to or from the EoAT 206.

FIG. 30 shows an enlarged perspective view of the mast facing end 2318of the EoAT 206 with selective components removed to improve visibility.As shown, a gripper drive 3002 is configured to move the grippermechanism 2302 along the drive tracks 2308 between the extended andretracted positions. In one form, the gripper drive 3002 is in the formof a reversible servomotor, but in other examples, the gripper drive3002 can include other types of motors, such as pneumatic motors. Agripper driveshaft 3004 is operatively connected to the gripper drive3002 via a drive belt 3006. At both ends, the gripper driveshaft 3004has drive wheels 3008 that drive a gripper belt 3010. When driven by thegripper drive 3002, the gripper belt 3010 is configured to move thegripper mechanism 2302 along the drive tracks 2308.

FIGS. 31 and 32 respectively show front and rear perspective views ofthe gripper mechanism 2302 with the gripping section 2316, and FIGS. 33and 34 respectively show side and top views of the gripper mechanism2302 with the gripping section 2316. Along with the gripping section2316, the gripper mechanism 2302 includes a carriage 3102 that ridesalong the drive tracks 2308, a cam follower 3104 that rides along thecam tracks 2312, and an extension mechanism 3106 for verticallyextending and retracting the gripping section 2316 from the carriage3102. The carriage 3102 includes one or more belt clamps 3108 that clampto the gripper belt 3010. The belt clamps 3108 extend through the guideslot 2310 in the drive tracks 2308 in order to clamp to the gripper belt3010. In other forms, the carriage 3102 can be secured to the gripperbelt 3010 in other manners, and the carriage 3102 can be driven by othertypes of devices, such as via a pneumatic piston. The carriage 3102further includes one or more guide wheels 3110 that are received in theguide slots 2310 in the drive tracks 2308. The guide wheels 3110 insidethe guide slots 2310 help to smoothly guide the carriage 3102 along thedrive tracks 2308. A crossbeam 3112 connects both sides of the carriage3102 together.

The cam follower 3104 includes one or more cam follower arms 3114 withcam follower wheels 3116 that ride along the cam surfaces 2314 of thecam tracks 2312. As shown, the cam follower arms 3114 are connected tothe gripping section 2316. In the depicted example, the gripping section2316 is bolted to the cam follower 3104 so as to facilitate easyreplacement and repair, but in other examples, the gripping section 2316can be secured to the cam follower 3104 in other ways. The extensionmechanism 3106 connects the cam follower arms 3114 to the carriage 3102.In the illustrated example, the extension mechanism 3106 includes one ormore extension linkages 3118 that connect the carriage 3102 to the camfollower arms 3114. As should be appreciated, the extension linkages3118 form a parallelogram linkage type connection between the carriage3102 and the cam follower 3104 so that the cam follower 3104 remainsgenerally parallel to the carriage 3102 during extension and retractionof the gripping section 2316. This in turn allows the gripping section2316 to generally remain at an orientation facing the cargo item 110before, during, and after engagement with the cargo item 110 so as toensure a firm grip. In one form, the extension mechanism 3106 includesone or more biasing springs that bias the extension mechanism so thatthe gripping section 2316 is normally in a retracted position. In otherexamples, gravity is used to bias the gripping section 2316 into theretracted position.

The gripping section 2316 includes a manifold 3120 that provides avacuum or suction (i.e., low air pressure) to one or more vacuum orsuction cups 3122. In the illustrated example, the gripping section 2316includes three vacuum cups 3122, but in other examples, the grippingsection 2316 can include more or less vacuum cups 3122 than is shown.Referring to FIGS. 32 and 34, the manifold 3120 has a vacuum port 3202that supplies the vacuum to the manifold 3120 via a tube connected to avacuum supply. In the depicted example, the manifold 3120 includes asingle vacuum port 3202 that supplies the vacuum to all three vacuumcups 3122, but in other examples, each vacuum cup 3122 can include adedicated vacuum supply so that each vacuum cup 3122 can beindependently controlled. The vacuum cups 3122 help the grippermechanism 2302 to readily grab one side of a cargo item 110, such as abox, which is quite helpful when the cargo items 110 are tightly stackedor nested together. It should be recognized that other types of grippingmechanisms, such as clamps and/or robotic fingers, can be used inaddition or as an alternative to the vacuum cups 3122.

A technique for extending and retracting (and vice versa) of the grippermechanism 2302 will now be initially described with reference to FIGS.35 and 36. FIGS. 35 and 36 show partial cross-sectional side views ofthe EoAT 206 when the gripper mechanism 2302 is in the retractedposition and the extended position, respectively. As shown in FIG. 35,when the gripper mechanism 2302 is in the retracted position, thegripping section 2316 along with the rest of the gripper mechanism 2302is positioned at or below the top of the conveyor belts 2710 of theconveyor system 2304. FIG. 37 shows an enlarged partial cross-sectionalview of the gripper mechanism 2302 and the cam tracks 2312 when thegripper mechanism 2302 is in the retracted position. Again, thisretraction of the gripping section 2316 allows cargo items 110 tosmoothly move along the conveyor system 2304 without any interference.As shown, the cam follower wheels 3116 of the cam follower 3104 arelocated on the retracted sections 2906 of the cam surfaces 2314. Oncemore, biasing springs and/or gravity bias the gripping section 2316towards the retracted position below the top of the conveyor system2304.

To extend the gripper mechanism 2302 from the retracted position (FIG.35) to the extended position (FIG. 36), the gripper drive 3002 (FIG. 30)drives the gripper belt 3010 so that the carriage 3102 of the grippermechanism 2302 moves from the mast facing end 2318 towards the cargofacing end 2320. As the gripper belt 3010 moves the gripper mechanism2302, the guide slots 2310 in the drive tracks 2308 guide the guidewheels 3110 of the carriage 3102 so that the gripper mechanism 2302generally moves in a linear fashion along the EoAT 206. At the sametime, the cam follower wheels 3116 ride along the cam surfaces 2314 ofthe cam tracks 2312. Starting at the transition section 2908, the camfollower 3104 causes the extension mechanism 3106 to raise the grippingsection 2316 above the conveyor system 2304. Once the cam followerwheels 3116 reach the engagement section 2910 of the cam surfaces 2314,the gripping section 2316 fully extends above the conveyor belts 2710.The gripping section 2316 generally remains at the same relativeposition as the cam follower 3104 travels along the engagement section2910. Upon the gripper mechanism 2302 reaching the cargo facing end2320, the gripper drive 3002 ceases driving the drive belt 3006 suchthat the gripping section 2316 remains at the extended position, as isillustrated in FIG. 36. This movement of the gripper mechanism 2302 canbe sensed by the cargo sensor system 2322 (e.g., the cargo facing sensor2326) and/or other sensors. FIG. 38 shows an enlarged partialcross-sectional view of the gripper mechanism 2302 upon reaching thecargo facing end 2320. As can be seen, the cam follower wheel 3116 ispositioned in the extended section 2912 of the cam surface 2314. Theextended section 2912 is generally lower than the engagement section2910 so that the gripping section 2316 is positioned closer to thebottom of the cargo item 110.

To retract the gripper mechanism 2302 back towards the mast facing end2318, the process is reversed. The gripper drive 3002 is reversed todrive the gripper belt 3010 in a reverse direction. This movement pullsthe gripper mechanism 2302 back towards the mast facing end 2318.Typically, but not always, the gripper mechanism 2302 is moved fasterthan the conveyor belts 2710 on the EoAT 206 to facilitate loading orunloading of the cargo items 110 from the conveyor belts 2710. In oneform, the conveyor belts 2710 are driven at a speed of around 200 feetper second (about 61 meters/second). The carriage 3102 is guided backalong the guide slots 2310 in the drive tracks 2308. The cam followerwheels 3116 at the same time ride along the cam surfaces 2314 of the camtracks 2312. Like before, the cam follower 3104 causes the grippingsection 2316 of the gripper mechanism 2302 to extend above the conveyorsystem 2304 when riding along the engagement section 2910 of the camtracks 2312. In one example, the gripper drive 3002 varies the travelspeed of the gripper mechanism 2302 as the gripper mechanism 2302travels along the cam surfaces 2314. Similar to a car traveling over aspeed bump, the gripper drive 3002 reduces the speed of the grippermechanism 2302 during transition between the extended section 2912 andthe engagement section 2910. The speed of the gripper mechanism 2302 inthis example is also reduced when moving along the transition section2908. It should be recognized that the speed of the gripping mechanism2302 can have different velocity profiles due to a number of factors,including, but not limited to, the type or size of cargo item 110 beingprocessed, the desired processing speeds, conveyor speeds, profiles ofthe cam surfaces 2314, and/or type of gripper mechanism 2302 being used.Upon reaching the transition section 2908, the cam follower 3104 causesthe gripping section 2316 to start moving in a downwards direction belowthe conveyor belts 2710. Once the cam follower wheels 3116 reach theretracted section 2906, the gripper mechanism 2302 is retracted out ofthe way and below the top surface of the conveyor system 2304, therebyallowing cargo items 110 to have uninterrupted travel along the conveyorsystem 2304 in either direction.

To detect the location and/or orientation of the cargo items 110 whenfor example in the cargo carrier 108, the robot 102 in FIG. 39 includesone or more cargo sensors 3902. In the illustrated example, the cargosensor 3902 is mounted underneath the mast 204 so that the cargo sensor3902 generally has a clear sight and is generally not blocked by thegripper mechanism 2302. It however should be recognized that the cargosensor 3902 can be positioned elsewhere on the robot 102. In one form,the cargo sensor 3902 is a camera 3904 for a vision system that sensesthe edges of the cargo items 110, and in one particular example, thecargo sensor is a vision system produced by Graftek Imaging, Inc. ofAustin, Tex. In the illustrated example, the cargo sensor 3902 includesthe camera 3904 with two light bars 3906. The light bars 3906 arehorizontally oriented and positioned above and below the camera 3904which includes lens and bracketry. As indicated by double arrow 3908,the cargo sensor 3902 is located or recessed at a distance away from theend of the mast 204 where the mast 204 is joined to the EoAT 206. In oneparticular example, the cargo sensor 3902 is a vision system thatincludes two 24 inch horizontal light bars 3906 with a 3 inch clearancediameter, and the light bars 3906 along with the camera 3904 occupy,roughly, 6 cubic inches of space. In this example, the distance 3908from the cargo sensor 3902 to the tip of the mast 204 is about 2 meters,and the cargo sensor 3902 occupies approximately 27 inches of verticalspace below the mast 204. It is envisioned that alternate orientations,configurations, and/or locations of the cargo sensor 3902 can be devisedfor the robot 102. For example, one or more of the cameras 3904 and/orlight bars 3906 can be mounted to the top or side of the mast 204 aswell as on the base unit 202, EoAT 206, and/or not on the robot 102.Other types of sensors, such as laser curtains, ultrasonic detectors,and the like, can also be used. Note that the cargo sensor 3902 in FIG.39 is illustrated generally larger than what is used commercially toenhance visibility in the drawings. In practice, the cargo sensor 3902can be smaller or larger than is illustrated. By sensing the edges ofthe cargo items 110, the robot 102 is able to properly position the EoAT206 during stacking and unstacking of the cargo items 110.

The cargo sensor 3902 is capable of capturing multiple images throughoutthe picking (or placing) process to acquire the needed data of the cargocontainer environment and cargo load. Correspondingly, a few images(e.g., one to five) could be acquired at the beginning of the loading orunloading process to provide the data of the trailer environment andcargo load for the robot 102. In one particular example, the camera 3904takes one or more pictures of the cargo items 110 (and/or theenvironment of the cargo carrier 108) before the unloading or loadingprocess of the cargo items 110. The controllers 210 of the robot 102 usethese static pictures as a map for controlling the movement of the EoAT206 as well as other components of the robot 102. In another example,the camera 3904 takes a series of pictures, once each time a row,column, stack, and/or individual cargo item 110 is processed, and thecontrollers 210 control the operation of the robot 102 based on theseseries of pictures. In still yet another example, the camera 3904 gatherimages of the cargo items 110 in a continuous (e.g., video) or nearcontinuous manner which are then processed by one or more of thecontrollers 210.

An example showing how the cargo item 110 is loaded onto the EoAT 206will now be described with reference to FIGS. 40-45. As will beappreciated, the process steps and order of the drawings can be reversedto show how the cargo item 110 is unloaded from the EoAT 206. Turning toFIG. 40, based on the location of the cargo item 110 sensed by the cargosensor 3902, the transport system 208, mast actuator system 212, and theEoAT pitch-yaw actuator joint 1802 position the cargo facing end 2320 ofthe EoAT 206 in close proximity to the cargo item 110. Once in position,the gripper mechanism 2302 is moved from the retracted position, whichis shown in FIG. 40, to the extended position, as is shown in FIGS. 41and 42. A vacuum is applied to the vacuum cups 3122 in order to securethe cargo item 110 to the gripper mechanism 2302. As illustrated in FIG.42, the vacuum cups 3122 of the gripping section 2316 engage near thebottom of the cargo item 110. Securing at that position helps withlifting the cargo item 110 onto the EoAT 206. Before hand or when thecargo item 110 is secured, the conveyor system 2304 drives the conveyorbelts 2710 in a direction so that the cargo item 110 is moved from thecargo facing end 2320 to the mast facing end 2318. In another example,the conveyor system 2304 can be continuously driven. In another example,the conveyor belts 2710 are not driven until or after the cargo item 110is loaded onto the conveyor belts 2710. In the illustrated example, thevacuum cups 3122 are secured to or engage one cargo item 110 at a time.However, in other examples the EoAT 206 can be used to load, and/orunload more than one cargo items 110 at a time so as to enhance cycletime. For instance, the EoAT 206 can load and/or unload cargo items 110that are stacked upon one another.

Upon sensing the cargo item 110 is secured to the gripper mechanism 2302(e.g., by sensing a change in pressure at the vacuum cups 3122, viacargo sensor system 2322, and/or via cargo sensor 3902), the grippermechanism 2302 is moved from the cargo facing end 2320 to the mastfacing end 2318 so as to pull the cargo item 110 onto the conveyor belts2710, as is depicted in FIG. 43. Once the cargo item 110 is fully loadedonto the EoAT 206, as for example sensed by the cargo sensor system2322, the vacuum cups 3122 can be released from the cargo item 110. Thegripper mechanism 2302 can then be accelerated faster than the conveyorbelts 2710 so that the gripper mechanism 2302 is released from the cargoitem 110. At or upon reaching the retracted position, the grippingsection 2316 is retracted below the bottom of the cargo item 110 suchthat the cargo item 110 can travel over the gripper mechanism 2302, asis depicted in FIGS. 44 and 45. In one form, the mast facing sensor 2324is used to sense when the cargo item is transferred from the EoAT 206 tothe mast 204. The EoAT 206 then can be moved to grab on another cargoitem 110. The cargo items 110 from the EoAT 206 travel along the mast204 and are transferred from the robot 102 onto the extendable conveyorsystem 104 which in turn transfers the cargo item 110 to the conveyorsystem 106.

As alluded to before, the operation of the EoAT 206 can be reversed inorder to stack the cargo items 110 in for example the cargo carrier 108.The EoAT 206 is positioned at the desired location where the cargo item110 is to be stacked. The mast facing sensor 2324 can sense when one ofthe cargo items 110 is on the EoAT 206 (FIGS. 44 and 45). Upon the cargofacing sensor 2326 (or other sensor) sensing the cargo item 110 isapproaching the cargo facing end 2320 of the EoAT 206, the grippermechanism 2302 is moved from the retracted position to the extendedposition so as to push against the side of the cargo item 110. In oneform, the vacuum cups 3122 are activated to grip the cargo item 110, andin another example, the vacuum cups 3122 are not activated and merelypush against the cargo item 110. In a further example, the cargo items110 are conveyed off the conveyor system 2304 of the EoAT 206 at highspeed such that the gripper mechanism 2302 is not needed to push thecargo items 110 from the EoAT 206. The mast facing sensor 2324 senseswhen the cargo item 110 is positioned off of the EoAT 206. Moving to thefully extended position, the gripper mechanism 2302 pushes the cargoitem 110 into place within the stack. Once the cargo item 110 isstacked, the suction of the vacuum cups 3122 is released, and thegripper mechanism 2302 is retracted to the fully retracted position soas to allow the next cargo item 110 to be loaded onto the EoAT 206. Instill yet another variation, the gripper mechanism 2302 is not actuatedwhen stacking cargo items 110, and only the conveyor system 2304 is usedto stack the cargo items 110.

A block diagram 4600 showing one example of the overall controlarchitecture for the robot 102 is shown in FIG. 46. As illustrated, apower source 4602 provides power to the robot 102. As noted before, therobot 102 in one example receives power from an external power source4602, but in other examples, the robot 102 can include an internal powersource, such as batteries. A cable reel 4604 is used to take up anyslack of the electrical cable plugged into the power source 4602. Asdepicted, the cable reel 4604 is electrically connected to a disconnect4606 (e.g., a circuit breaker box) that is configured to electricallydisconnect or isolate the robot 102 from the power source 4602, such asduring an unexpected power surge. The disconnect 4606 is electricallyconnected to a transformer 4608 and a drive bus 4610. The transformer4608 down converts the power so that it can be used by the variouscontrollers 210 and sensors in the robot 102. The transformer 4608provides power to a PLC 4612 and a safety configurable relay 4614. ThePLC 4612 controls the general operation of the robot 102. The safetyconfigurable relay 4614 is used to determine when certain operationalsafety limits are exceeded so that the PLC 4612 can take appropriatecorrective action, such as when motors reach a torque or speed limit.The PLC 4612 communicates with a number of different sensors andcontrollers. For instance, the PLC 4612 is operatively connected to EoATsensors/controllers 4616. The EoAT sensors/controllers 4616 can includevacuum switches that control the operation of the vacuum cups 3122 andthe cargo sensor system 2322. The PLC 4612 is operatively connected tothe safety configurable relay 4614 which as is shown is connected to anumber of other components. For instance, safety scanner/light curtains4618 are operatively connected to the safety configurable relay 4614.The safety scanners 4618 can include the above discussed safety scanners228 that detect objects, individuals, and structures around the robot102 so that the robot 102 can be steered for collision avoidance orpositioning. The PLC 4612 is also operatively connected directly tothese components through the drive bus 4610.

As illustrated in FIG. 26, the drive bus 4610 connects a number ofcomponents, such as motors, motor controllers, and/or sensors, togetherso that the components can communicate with one another and the PLC4612. In the illustrated example, the components are connected togetherusing an Ethernet communication type system, but in other examples othertypes of communication protocols and/or systems can be used. The PLC4612 through the drive bus 4610 can control the operation of a number ofcomponents, such as the previously described motors. The safetyconfigurable relay 4614 also directly monitors the operations of thesecomponents. For example, the safety configurable relay 4614 monitors thetorque and the speed of the motors to prevent damage and/or injury. Asillustrated, a base motion controller 4620 controls the movement of therobot 102 through the operation of the wheel motors 604, and a basicsteering controller 4622 controls the steering of the robot 102 throughthe steering motors 802. The PLC 4612 controls the yaw of the mast 204through a slew ring or yaw controller 4624 which controls the operationof the mast yaw drive 908. The PLC 4612 through a main linkagecontroller 4626 controls the operation of the extension 1304 and pitch1306 drive motors so as to control the pitch and yaw of the mast 204. AnEoAT pitch or tilt controller 4628 controls the operation of the EoATpitch motor 1614 so as to control the pitch (or tilt) of the EoAT 206.The PLC 4612 is also operatively connected via the drive bus 4610 to anEoAT yaw controller 4630. The EoAT yaw controller 4630 controls theoperation of the EoAT yaw motor 1904 so as to control the yaw of theEoAT 206. First 4632 and second 4634 lower conveyor controllersrespectively control the operation of the mast section 216 andtransition section 218 of the base unit conveyor 214. The PLC 4612 isable to control the operation of the motor 1608 of the mast conveyor1404 via the mast conveyor controller 4636. It should be recognized thatother components can be operatively connected to and be controlled bythe PLC 4612 through the drive bus 4610. For example, the conveyor drive2702 and the gripper drive 3002 on the EoAT 206 are also operativelyconnected to the drive bus 4610 so that the PLC 4612 is able to controlthe operation of the EoAT 206.

The general operation of the robot 102 will now be described withreference to FIGS. 47 and 48. In this particular example, the operationof the robot 102 will be described with reference to unloading the cargoitems 110 from the cargo carrier 108, but it should be recognized thatthe operation can generally be reversed in order to load the cargo items110 into the cargo carrier 108. Since the operation and function of theEoAT 206 has already been described in great detail with reference toFIGS. 40-45 as well as in the other drawings, these specific operationaldetails of the EoAT 206 will not be described again for the sake ofbrevity, but please refer to the previous description. Once the cargocarrier 108, such as a semitrailer, is positioned at the loading dock114 and that the door for the cargo carrier 108 is opened, the transportsystem 208 of the base unit 202 moves the robot 102 into properposition. As shown, the cargo items 110 inside the cargo carrier 108 arestacked on top of one another to form columns 4702 of the cargo items110. Multiple columns 4702 of the cargo items 110 form walls or rows4704 of the cargo items 110. In one example, the robot 102 via the mast204 positions the EoAT 206 at the top corner of one of the rows 4704. Asexplained before, the cargo sensor 3902 senses a target cargo item 110that the EoAT 206 will grab, and the EoAT pitch-yaw actuator joint 1802along with the mast 204 properly positions the EoAT 206 at the targetcargo item 110. As explained before with respect to FIGS. 40-45, thegripper mechanism 2302 is extended to grab the target cargo item 110 andpull the target cargo item 110 onto the EoAT 206. Once the cargo item110 is securely placed on the conveyor system 2304 of the EoAT 206, thegripper mechanism 2302 is retracted out of the way, and the conveyorsystem 2304 transports the cargo item 110 onto the mast 204. The mast204 then moves the EoAT 206 to the next column 4702 in the row 4704 inorder to grab the next cargo item 110 in the same fashion. The cargoitems are transported along the mast 204 via the mast conveyor 1404 in acontinuous or near continuous fashion. The mast conveyor 1404 thentransfers the cargo item 110 onto the base unit conveyor 214 which inturn transfers the cargo item 110 onto the extendable conveyor 104. Asmentioned before, the extendable conveyor 104 transfers the cargo itemsonto the conveyor system 106. The robot 102 moves the EoAT 206 in aS-shaped or raster pattern along the row 4704 of cargo items 110. Asmentioned before, the EoAT 206 is designed to pull the cargo itemsdirectly from the floor of the cargo carrier 108. Once a row 4704 ofcargo items is emptied, the transport system 208 moves the base unit 202so that the EoAT 206 is positioned at the next row 4704 of cargo items110. The robot 102 continues unloading the cargo items by positioningthe EoAT 206 at the top corner of the cargo items 110 in the row 4704,and the EoAT 206 unloads the cargo items 110 by moving in a similarS-shaped or serpentine pattern down the row of the cargo items 110. Asthe base unit 202 to progressively moves inside the cargo carrier 108,which is shown in FIGS. 1 and 48, the extendable conveyor 104 extends soas to preserve the connection between the robot 102 and the mainconveyor system 106. Once the cargo carrier 108 is emptied, the robot102 is moved out of the cargo carrier 108 so that the next cargo carrier108 can be serviced.

To load cargo items 110 into the cargo carrier 108, the process isgenerally reversed. The robot 102 is moved inside the cargo carrier 108so that the EoAT 206 is close to the back wall of the cargo carrier 108.Cargo items 110 from the main conveyor 106 are transported to the robot102 via the extendable conveyor 104. The EoAT 206 is positioned close toa bottom corner of the back wall, and the EoAT places the cargo item 110onto the floor of the cargo carrier 108. The EoAT 206 move horizontallyalong the floor of the cargo carrier 108 to form a single row 4704 ofthe cargo items 110. The EoAT 206 is then lifted to a position so thatthe next level of cargo items 110 can be placed or stacked on top of thepreviously placed cargo items 110 in the row 4704. The EoAT 206 is movedin an S-shaped or raster pattern to complete the row 4704 of cargo items110. Once the row 4704 is complete, the robot 102 is driven backwards sothat the EoAT 206 can form the next row 4704 of cargo items 110. Thesame packing process continues until the cargo carrier 108 is fullyloaded with the cargo items 110.

FIG. 49 shows an example of another type of automated loading andunloading robot 4902 that can be used in the system 100. The robot 4902in FIG. 49 has most of the same components as that of the robot 102illustrated in FIG. 2, and for the sake of clarity as well as brevity,these common components will not be discussed, but reference is made tothe previous discussion. The only difference between the robot 4902 inFIG. 49 and the previously discussed robot 102 is that the robot 4902 inFIG. 49 includes a counterbalance arm 4904 instead of the air springs1222 for the mast counterbalance system 1220. The counterbalance arm4904 is designed to provide enough weight to provide a counterbalance tothe weight of the mast 204 and EoAT 206 and any cargo items 110. Itshould be recognized that in other examples other types ofcounterbalance systems 1220 can alternatively or additionally be used.

FIG. 50 illustrates a perspective view of a robot 5000 according toanother example. In FIG. 50, selected components such as the controllers210 and the base unit housing 224 have been removed to improvevisibility. As will be appreciated, the robot 5000 has most of itscomponents in common with the previously discussed robot 102, such asthe mast 204 and EoAT 206. For the sake of clarity as well as brevity,these common components will not be discussed again below. The robot5000 has a base unit 5002 that is constructed in a fashion similar tothe one previously discussed. Like before, the base unit 5002 has theframe 502, wheels 504, steering chains 704, and steering motor 802. Inthe illustrated example, the chains 704 not only link the rear wheels504 to the steering motor 802 but also the front wheels 504 so that thesteering motor 802 is able to steer both sets of wheels 504. The baseunit 5002 further includes the mast yaw control subsystem 902 and mastpitch-extension control subsystem 904 with subcomponents that areslightly different than those described before.

As shown, the mast pitch-extension control subsystem 904 in the mastactuator system 212 include linkages 5004 that connect the mast 204 to amast base 5006. The height of the mast 204 (relative to the floor) at aneutral, level position is set so that the EoAT 206 is positioned at ornear the middle of an average stack height of cargo items 110 in thecargo carrier 108. In the illustrated example, the mast pitch-extensioncontrol subsystem 904 includes a pair of rocker mechanisms for movingthe mast 204. The rocker mechanisms are formed by the linkages 5004, andthese linkages 5004 in part include a mast extension arm 5008 that ispivotally connected to the mast base 5006 at one end via an extensionarm coupling (or bearings) 1206 and pivotally connected to the mast 204at the other end. Pivotal movement of the mast extension arm 5008 causesthe mast 204 along with the EoAT 206 to move horizontally in thelongitudinal direction 506 of the robot 5000. In other words, pivotingof the mast extension arm 5008 causes the EoAT 206 to extend or retractwhile the base unit 5002 remains stationary, if so desired. Tofacilitate this, the extension drive 1208 has an extension crank 5010that is connected to the mast extension arm 5008 via an extension link5012. As the extension drive 1208 rotates the extension crank 5010, themast extension arm 5008 pivots about the extension arm coupling 1206 toextend or retract the EoAT 206 via the mast 204.

A mast pitch arm 5014 is used to control the pitch or vertical movementof the mast 204. The pitch drive 1216 is operatively connected to themast pitch arm 5014 via a pitch crank 5016. The pitch drive 1216 is ableto control the pitch of the mast 204 via the pitch crank 5016 and mastpitch arm 5014. This in turn allows the pitch drive 1216 to control thevertical location of the EoAT 206. As noted before, the extension drive1208 via the mast extension arm 5008 typically, but not always, works inconjunction with the pitch drive 1216 to ensure that the EoAT 206 isproperly positioned so as to still be able to engage with the cargoitems 110 as the pitch of the mast 204 changes. The mast counterbalancesystem 1220 in the illustrated example includes two air springs 1222that are coupled between the mast 204 and the mast base 5006. As shown,the mast base 906 includes air spring connectors 5018 to which the airsprings 1222 are pivotally connected. In the illustrated example, themast counterbalance system 1220 includes a pair of the air springs 1222,but more or less can be used in other examples. In the depicted example,the air springs 1222 are connected to the mast 204 between the mastextension arm 5008 and the mast pitch arm 5014.

FIGS. 51 and 52 respectively illustrate top and bottom perspective viewsof the mast base 5006. The mast base 5006 includes a connector section5102 where the mast base 5006 is connected to a mast yaw drive gearbox5302 that is powered by the mast yaw drive motor 5304. In one form, theconnector section 5102 of the mast base 5006 is bolted to the mast yawdrive gearbox 5302, but these components can be connected in other ways.The mast yaw drive gearbox 5302 is mounted to the frame 502. Through themast yaw drive gearbox 5302, the mast yaw drive motor 5304 is able tochange the yaw of the mast 204 which in turn changes the location of theEoAT 206.

FIG. 54 illustrates a perspective view of a robot 5400 according toanother example. In FIGS. 54, 55, 56, and 57, selected components suchas the base unit housing 224 have been removed to improve visibility. Aswill be appreciated, the robot 5400 has most of its components in commonwith the previously discussed robots 102, 5000, such as the mast 204,EoAT 206, controllers 210, actuator system 212, and base unit conveyor214, with just a few modifications. For the sake of clarity as well asbrevity, these common components will not be discussed again below, butplease refer to the previous discussion of these common features. Therobot 5400 has a base unit 5402 that is constructed in a fashion similarto the ones previously discussed. Like before, the base unit 5402 has aframe 5404, wheels 504, steering belts or chains 5406, and the steeringmotor 802. In the illustrated example, steering belts 5406 are used tosteer the wheels 504 via the steering motor 802, but in other examples,chains can be used to steer the wheels 504 in the same manner asdescribed before. The steering belts 5406 not only link the rear wheels504 to the steering motor 802 but also the front wheels 504 so that thesteering motor 802 is able to steer both sets of wheels 504. The wheels504 are able to be turned at least ninety degrees (90°) relative to thelongitudinal axis of the robot 5400 so that the robot 5400 is able tomove laterally between loading docks. In the example illustrated in FIG.57, cater-corner wheels 504 are powered by wheel motors 604, and theother wheels 504 are unpowered. This configuration helps enhancemovement of the robot 5400 and reduces issues in coordinating operationof the wheel motors 604. Looking at FIGS. 54 and 55, the mast 204 andother components of the robot 5400 in the illustrated example haveguides 5408 that are configured to guide cables and/or hoses of therobot 5408. In a similar fashion as described before with respect toFIG. 53, the mast yaw drive motor 5304 is able to change the yaw of themast 204 which in turn changes the location of the EoAT 206

FIG. 58 shows an enlarged top perspective view of the robot 5400 at theEoAT 206. The EoAT 206 is configured and operates in the same manner asdescribed before, but the EoAT 206 has an EoAT pitch-yaw actuator joint5802 connected between the EoAT 206 and the mast 204 that is configuredslightly differently than the ones described before. For example, thejoint 5802 has mast conveyor pulleys 5804 around which conveyor belts5806 for the mast are looped. With this configuration, the mast conveyorbelts 5806 can be positioned closer to the EoAT 206 so as to minimizeconveyor belt gapping between the mast 204 and EoAT 206. FIG. 58 furthershows additional components of the EoAT 206, such as such a cable trackor race 5808 and one or more vacuum control valves 5810 that control thevacuum to the individual vacuum cups 3122 on the gripper mechanism 2302.Like before, the EoAT pitch-yaw actuator joint 5802 is able to controlthe pitch 1804 and yaw 1806 (FIG. 18) movement of the EoAT 206.

FIGS. 59 and 60 respectively show top and bottom perspective views ofthe EoAT pitch-yaw actuator joint 5802. The joint 5802 includes an EoATbracket 5902 that is secured to the EoAT 206 such as via bolts and/or inother manners. The EoAT bracket 5902 has a first flange 5904 with apivot pin opening 5905, a second flange 5906, and a connector plate 5908that connects the first 5904 and second 5906 flanges together. The firstflange 5904 and the second flange 5906 define a bracket cavity 5907. Thejoint 5802 further includes a pivot block or housing 5910 positioned inthe bracket cavity 5907, one or more drive pulleys 5912, and one or moreshaft bearing guides 5914. In the illustrated example, the shaft bearingguides 5914 are sandwiched between the drive pulleys 5912 and the pivothousing 5910. The shaft bearing guides 5914 are configured to secure theyaw-actuator joint 5802 to the mast 204 such as via bolts and/or inother manners. The pivot pin opening 5905 in the first flange 5904 isconfigured to receive a yaw pivot pin or shaft 5916. Turning to FIG. 60,the second flange 5906 has one or more bolt opening 6002 that areconfigured to receive one or more bolts 6004. In the illustratedexample, the bolt opening 6002 are arranged in a circular pattern. Thebolts 6004 transmit torque from the internal workings of theyaw-actuator joint 5802 in order to adjust the yaw of the EoAT 206. Asshould be appreciated, other types of fasteners or systems for securingcan be used to transfer torque in other examples besides the bolts 6004.

FIG. 61 shows a partial perspective view of the yaw-actuator joint 5802with selected components removed to enhance visibility. The pivothousing 5910 has a flange cavity 6102 in which the first flange 5904 isreceived. On opposing sides of the flange cavity 6102, the pivot housing5910 has stop surfaces 6104 that can limit the rotational movement ofthe first flange 5904 which in turn limits the yaw movement of the EoAT206. The pivot housing 5910 further defines a shaft bearing cavity 6106in which a shaft bearing or guide 6108 facilitates rotation of the yawpivot shaft 5916.

FIG. 62 shows a perspective view of the yaw-actuator joint 5802 with thepivot housing 5910 and other components removed. As shown in FIG. 62,the joint 5802 includes one or more pinion gears 6202 that engage a rackgear 6104. In the illustrated example, two pinion gears 6202 engage therack gear 6104 on opposite sides of the yaw pivot shaft 5916, but otherexamples can include more or less gears 6202, 6104. The pivot pin gears6202 each include a gearhead 6206 with gear teeth 6208 that engage therack gear 6104 and a gear shaft 6110 that connects the gearhead 6206 tothe drive pulley 5912. In the illustrated example, the gear teeth 6208,6216 are helical type gear teeth to ensure proper engagement, especiallywhen high torques are applied, but other types of teeth arrangements canbe used in other examples. In the illustrated example, the pinion gears6202 and the rack gear 6204 are in a battle gear type arrangement, butthese gears 6202, 6204 can be arranged differently in other examples.Bearings 6112 along the shaft 6110 facilitate rotation of the piniongear 6102 within the pivot housing 5910. The rack gear 6104 has agearhead 6114 with gear teeth 6116 that engage the teeth 6108 of thepinion gear 6102 and a gear shaft 6118 that is secured to the secondflange 5906 of the EoAT bracket 5902 via the bolts 6004 (FIG. 60). Acover bearing 6220 surrounds the gear shaft 6218 of the rack gear 6204to allow the rack gear 2104 to rotate relative to the pivot housing5910. Bearings 6222 around the pin 5912 allow the shaft 5916 to rotaterelative to the housing 5910 and the rack gear 6204.

FIGS. 63 and 64 respectively show top perspective and bottom perspectiveviews of the pivot housing 5912. As shown, the pivot housing 5912 at theshaft bearing cavity 6106 defines a shaft channel 6302 that extendscompletely through the pivot housing 5912 so as to receive the yaw pivotshaft 5916. Transverse or perpendicular to the shaft channel 6302, thepivot housing 5912 has opposing pinion cavities 6304 in which the piniongears 6202 are disposed. Generally around the shaft channel 6302, thepinion cavities 6304 are closed by the pivot housing 5912, but proximalto be rack gear 6204 the pinion cavity 6304 defines gear engagementchannel 6306 through which the pinion gears 6202 are able to engage therack gear 6204. Looking at FIG. 64, the gear engagement channel 6306from the pinion cavity 6304 opens into rack cavity 6402 where the rackgear 6204 is disposed.

Operation of the yaw-actuator joint 5802 will now be described withreference to FIG. 65. The pinion 6202 and rack 6204 gears can rotate inboth directions (i.e., clockwise or counterclockwise). The pinion gears6202 are rotated by the drive pulleys 5912, and the drive pulleys 5912are in turn rotated by drive belts 6502. With the drive belts 6502, thepinion gears 6202 can be rotated in a clockwise or counterclockwisedirection. Each of the pinion gears 6202 are able to be rotatedindependently of one another by the drive belts 6502 so as to controlboth the pivotal and yaw orientation of the EoAT 206. To make a point ofclarification in the following description, the pinion gears 6202 willbe described as rotating in the “same direction” or in the “oppositedirection.” Since the pinion gear 6202 are facing one another, therotational direction referred to in this description is from the same,one perspective, that is, as viewed from the back of one of the piniongears 6202 and the front of the other or opposing pinion gear 6202. Forexample, when described rotating in the “same direction,” the face (orfront) of the gearhead 6206 with teeth 6208 of one of the pinion gears6202 can rotate in a clockwise direction, and the back of the gearhead6206 (i.e., facing the drive pulley 5912) likewise rotates in aclockwise direction as viewed from the same, single perspective.Conversely, when describing rotation in the “opposite direction,” theface of the gearhead 6206 of one of the pinion gears 6202 can rotate ina clockwise direction, and the back of the opposite gearhead 6206rotates in the opposite, counterclockwise direction when viewed from asingle perspective. As might be appreciated, having the pinion gears6202 described with reference to two different perspectives (i.e., theface of each pinion gear 6202) would make the description a bitconfusing, so the rotational directions of the pinion gear 6202 will bedescribed with respect to the one static perspective. For instance, inthe case where the pinion gears 6202 rotate in the same direction, whenviewed from the face of each of the gearheads 6206 (i.e., from theperspective of the yaw pivot shaft 5916), one of the pinion gears 6202would rotate in a clockwise direction and the other would rotate in acounterclockwise direction. Again, for the purposes of the descriptionbelow, the terms “same direction” and “opposite direction” whenreferring to the rotational direction of the pinion gears 6202 is from asingle viewpoint.

The yaw-actuator joint 5802 is configured to move the EoAT 206 in thepitch 1804 and/or yaw 1806 directions relative to the mast 204. To movethe EoAT 206 in the pitch direction 1804, the pinion gears 6202 arerotated in the same direction such that the rack gear 6204 does notrotate which in turn creates a torque that causes the EoAT 206 to pitch.For example from the perspective shown in FIG. 65, when the pinion gears6202 are rotated in the same counterclockwise direction, the EoAT 206pivots upwards relative to the mast 204 in the pitch direction 1804, andwhen the pinion gears 6202 are rotated in the same clockwise direction,the EoAT 206 pivots downwards relative to the mast 204 in the pitchdirection 1804. To change the yaw of the EoAT 206 relative to the mast204, the pinion gears 6202 are rotated in an opposite direction. Forinstance, when the pinion gears 6202 are rotated in the oppositedirection, the rack gear 6204 rotates. As mentioned before, the rackgear 6204 is fixed to the second flange 5906 of the EoAT bracket 5902such that when the rack gear 6204 rotates, the EoAT bracket 5902 rotatesabout the yaw pivot shaft 5916. This in turn causes the EoAT 206 to movein the yaw direction 1806 relative to the mast 204. The EoAT 206 canmove simultaneously in both the pitch 1804 and yaw 1806 directions byhaving a rotational velocity differential between the pair of piniongears 6202. As should be recognized, the gears can be configureddifferently in other examples such that the gears rotate in differentfashions in order to move the EoAT 206 in the pitch 1804 and yaw 1806directions. For instance, intermediate gearing can be placed between thepinion gears 6202 and the rack gears 6204 and/or oriented differently tofacilitate relative movement of the EoAT 206.

Turning to FIGS. 66 and 67, the base unit 5402 of the robot 5400 furtherincludes the mast yaw control subsystem 902 and mast pitch-extensioncontrol subsystem 904 with subcomponents similar to those described withrespect to FIG. 50. For the sake of clarity as well as brevity, thecommon components, functions, and operational modes will not be againdescribed in detail, but please refer to the previous description.

As shown, the mast pitch-extension control subsystem 904 includelinkages 6604 that connect the mast 204 to a mast base 6606. The heightof the mast 204 (relative to the floor) at a neutral, level position isset so that the EoAT 206 is positioned at or near the middle of anaverage stack height of cargo items 110 in the cargo carrier 108. In theillustrated example, the mast pitch-extension control subsystem 904includes a pair of rocker mechanisms for moving the mast 204. The rockermechanisms are formed by the linkages 6604, and these linkages 6604 inpart include a mast extension arm 6608 that is pivotally connected tothe mast base 6606 at one end and pivotally connected to the mast 204 atthe other end. Pivotal movement of the mast extension arm 6608 causesthe mast 204 along with the EoAT 206 to move horizontally in thelongitudinal direction 506 of the robot 5000. In other words, pivotingof the mast extension arm 6608 causes the EoAT 206 to extend or retractwhile the base unit 5402 remains stationary, if so desired. Tofacilitate this, the extension drive 1208 has an extension crank 6610that is connected to the mast extension arm 6608 via an extension link6612. As the extension drive 1208 rotates the extension crank 6610, themast extension arm 6608 pivots to extend or retract the EoAT 206 via themast 204.

A mast pitch arm 6614 is used to control the pitch or vertical movementof the mast 204. The pitch drive 1216 is operatively connected to themast pitch arm 5014 via a pitch crank 6616. The pitch drive 1216 is ableto control the pitch of the mast 204 via the pitch crank 6616 and mastpitch arm 6614. This in turn allows the pitch drive 1216 to control thevertical location of the EoAT 206. As noted before, the extension drive1208 via the mast extension arm 6608 typically, but not always, works inconjunction with the pitch drive 1216 to ensure that the EoAT 206 isproperly positioned so as to still be able to engage with the cargoitems 110 as the pitch of the mast 204 changes. The mast counterbalancesystem 1220 in the illustrated example includes one or more air springs1222 that are coupled between the mast 204 and the mast base 6606. Asshown, the mast base 6606 includes air spring connectors 5018 to whichthe air springs 1222 are pivotally connected. In the illustratedexample, the mast counterbalance system 1220 includes a pair of the airsprings 1222, but more or less can be used in other examples. In thedepicted example, the air springs 1222 are connected to the mast 204between the mast extension arm 6608 and the mast pitch arm 6614.

Referring to FIG. 67, as the mast 204 moves the base unit conveyor 214needs to compensate for changes in the distance, yaw, and pitch betweenthe base unit conveyor 214 and the mast 204. As noted before, the baseunit conveyor 214 includes the mast section 216 and the transitionsection 218 that are nested together so as to overlap. The mast section216 is able to move in a telescoping fashion relative to the transitionsection 218 so as to adjust for distance changes between the end of themast 204 and the end of the base unit 5402. In other words, the lengthof the base unit conveyor 214 is able to change as the mast 204 moves.The mast section 216 is connected to the transition section 218 of themast 204 via a mast connection joint 6702. The mast connection joint6702 is configured to compensate for both pitch and yaw changes betweenthe mast 204 and the transition section 218 is connected to the baseunit 5402 via a base connection joint 6704. The base connection joint6704 allows the base unit conveyor 214 to move in both the pitch 1804and yaw 1806 directions so as to compensate for the relative motion ofthe mast 204. A telescoping joint 6706 slidably connects the mastsection 216 to the transition section 218 in a telescoping manner.

FIG. 68 generally shows a top view of the base unit conveyor 214extending between the base unit 5402 and the mast 204. Both the mastsection 216 and the transition section 218 are self-powered such thattheir respective one or more conveyor belts 6802 are able to be poweredindependently of one another so as to operate at different speeds, if sodesired. In the illustrated example, the mast section 216 has a mastbelt motor 6804 that powers the conveyor belts 6802 on the mast section216, and the transition section 218 has a transition belt motor 6806that powers the conveyor belts 6802 on the transition section 218. Themotor 6804, 6806 are operatively connected to the conveyor belts 6802 ina fashion similar to that described above with respect to the mast 204.Both the mast 216 and transition 218 sections in the depicted examplehave a pair of conveyor belts 6802, but in other examples, the sections216, 218 can have more or less conveyor belts 6802 and/or can conveycargo items in other ways such as via rollers and slides, to name a few.

To compensate for multidirectional movement of the mast 204, the mastconnection joint 6702 in the illustrated example is in the form of aball joint. As shown, the mast connection joint 6702 includes a ballmember 6808 that is received inside a socket 6810. FIG. 69 shows anenlarged perspective view of the ball member 6808. As shown, the ballmember 6808 includes a stem 6902 connected to the mast section 216 and aball 6904 that is rotatably received into the socket 6810 connected tothe mast 204.

FIG. 70 shows a perspective view of the base unit conveyor 214 at thebase connection joint 6704. The base connection joint 6704 allows thebase unit conveyor 214 to move both in the pitch 1804 and yaw 1806directions. As illustrated, the base connection joint 6704 includes aconveyor shaft bracket 7002 that is rotatably coupled to the base unit5402 via a turntable joint 7004. The turntable joint 7004 allows thebase unit conveyor 214 to rotate or pivot in the yaw direction 1806. Theconveyor shaft bracket 7002 allows the base unit conveyor 214 to move inthe pitch direction 1804. The bracket 7002 includes one or more shaftflanges 7006 that define shaft openings 7008 that are configured toreceive a conveyor pulley shaft 7010. The shaft openings 7008 in oneform include bearings that reduce friction between the shaft flanges7006 and the conveyor pulley shaft 7010. At opposite ends, the conveyorpulley shaft 7010 has a conveyor pulley 7012 around which the conveyorbelts 6802 wrap as the belts 6802 to travel. The rotational connectionbetween the shaft bracket 7002 and the shaft 7010 allows the transitionsection 218 to pivot in the pitch direction 1804. It is envisioned thatthe base connection joint 6704 can include other types of joints tofacilitate movement between the base unit conveyor and the base unit5402 in other examples.

FIG. 71 shows a perspective view of the base unit conveyor 214 with asection of the transition section 218 removed so that the telescopingjoint 6706 is viewable. In the illustrated example, the telescopingjoint 6706 is in the form of a bearing rail. As depicted, thetelescoping joint 6706 includes a bearing rail 7102 that is secured to aframe 7104 of the mast section 216. In one form, the bearing rail 7102is positioned on opposing sides of the mast section 216 so as to engagethe transition section 218 at both sides. The transition section has abearing slide 7106 that is secured to a frame 7108 of the transitionsection 218. The bearing slide 7106 engages the bearing rail 7102 suchthat the bearing slide 7106 is able to generally smoothly slide alongthe bearing rail 7102. In other examples, other types of telescopicconnections can be used such as for example rack slides, compoundslides, and/or dovetail type slide connections.

In other examples, different types rails that are not necessarily flaredor even no rails at all can be used. For instance, a wall can be usedinstead of one or more of the rails 1406, 2306. In one particularexample illustrated in FIG. 72, an EoAT 7202, which is similar to thosedescribed before, includes one or more of guide rails 7204 that: (1)straight on a front end 7206; (2) longer than so the rail 7204 sticksout from the EoAT 7202, and (3) spring loaded 7208 from the sides.During loading, when the EoAT 7202 places the last case in the row, theEoAT 7202 has a tight fit between a wall 7210 and the adjacent case7212. By having the guide rails 7204 stick into the space between thewall 7201 and the adjacent case 7212 before the EoAT 7202 pushes thelast case off, the EoAT 7202 will have an increased success rate ofstacking the last case.

Glossary of Terms

The language used in the claims and specification is to only have itsplain and ordinary meaning, except as explicitly defined below. Thewords in these definitions are to only have their plain and ordinarymeaning. Such plain and ordinary meaning is inclusive of all consistentdictionary definitions from the most recently published Webster'sdictionaries and Random House dictionaries. As used in the specificationand claims, the following definitions apply to the following terms orcommon variations thereof:

Cargo or cargo items—is used in a broad sense to generally refer togoods or other physical objects that are typically carried or otherwisetransported on vehicles, such as on trucks, ships, aircraft, spacecraft,and/or motor vehicles. The cargo items can be unpackaged or packaged,such as in boxes, bags, bales, containers, barrels, and tanks, to namejust a few examples.

Cargo carrier—generally refers to any structure used to transport and/orstore cargo items, such as flatbed trailers, trailers, semitrailers,trucks, intermodal containers, refrigerated trailers, and railcars, tojust name a few examples. The cargo carrier can be transported in anynumber of ways, such as over land, sea, space, and/or air. Certain typeof cargo carriers, like intermodal containers, are designed to betransported in a number of manners, such as via a truck, in a ship, andvia rail. The cargo carrier can be fully enclosed, such as when in theform of a semi-trailer or cargo container, or open to the outsideenvironment, such as with a flatbed trailer.

Conveyor—is used in a broad sense to generally refer to a mechanism thatis used to transport something, like a cargo item. By way ofnon-limiting examples, the conveyor can include belt conveyors, wiremesh conveyors, chain conveyors, electric track conveyors, rollerconveyors, cross-belt conveyors, vibrating conveyors, and skate wheelconveyors, to name just a few. The conveyor all or in part can bepowered or unpowered. For instance, sections of the conveyors caninclude gravity feed sections.

Loading dock—generally refers to an area of a building or otherstructure where cargo items for cargo carriers (usually, but not always,road, rail, or sea) are loaded and unloaded. Cargo items can be alsostaged at the loading dock. Loading docks are commonly found oncommercial and industrial buildings, and warehouses in particular.Loading docks may be exterior, flush with the building envelope, orfully enclosed. Loading docks are not just limited to fully enclosedbuildings, but instead, can be located at locations that are partiallyor fully open to the outside environment.

Motor—generally refers to a machine that supplies motive power for adevice with moving parts. The motor can include rotor and linear typemotors. The motor can be powered in any number of ways, such as viaelectricity, internal combustion, pneumatics, and/or hydraulic powersources. By way of non-limiting examples, the motor can include aservomotor, a pneumatic motor, a hydraulic motor, a steam engine,pneumatic piston, hydraulic piston, and/or an internal combustionengine.

It should be noted that the singular forms “a”, “an”, “the”, and thelike as used in the description and/or the claims include the pluralforms unless expressly discussed otherwise. For example, if thespecification and/or claims refer to “a device” or “the device”, itincludes one or more of such devices.

It should be noted that directional terms, such as “up”, “down”, “top”“bottom”, “lateral”, “longitudinal”, “radial”, “circumferential”, etc.,are used herein solely for the convenience of the reader in order to aidin the reader's understanding of the illustrated embodiments, and it isnot the intent that the use of these directional terms in any mannerlimit the described, illustrated, and/or claimed features to a specificdirection and/or orientation.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges, equivalents, and modifications that come within the spirit ofthe inventions defined by following claims are desired to be protected.All publications, patents, and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication, patent, or patent application were specifically andindividually indicated to be incorporated by reference and set forth inits entirety herein.

The invention claimed is:
 1. A method, comprising: positioning an End ofArm Tool (EoAT) proximal a cargo item, wherein the EoAT has an EoATconveyor, wherein the EoAT includes a gripper mechanism with one or morevacuum cups; securing a cargo item with the vacuum cups of the grippermechanism; pulling the cargo item onto the EoAT conveyor with thegripper mechanism by moving the gripper mechanism along the EoAT;retracting the gripper mechanism at or underneath the EoAT conveyor to aretracted position; and moving the cargo item with the EoAT conveyorover the gripper mechanism when in the retracted position.
 2. The methodof claim 1, further comprising: wherein said positioning includes movingthe EoAT with a mast that is coupled to the EoAT; wherein the mastincludes a mast conveyor; and transferring the cargo item from the EoATconveyor to the mast conveyor.
 3. The method of claim 2, wherein: themast is coupled to a base unit; said positioning includes moving themast in a pitch direction relative to the base unit; and saidpositioning includes moving the mast in a yaw direction relative to thebase unit.
 4. The method of claim 3, wherein: said positioning includesmoving the EoAT in a pitch direction relative to the mast; and saidpositioning includes moving the EoAT in a yaw direction relative to themast.
 5. The method of claim 3, further comprising: wherein the baseunit includes a base unit conveyor; and conveying the cargo item fromthe mast conveyor to the base unit conveyor.
 6. The method of claim 2,wherein: said positioning includes moving the EoAT in a pitch directionrelative to the mast; and said positioning includes moving the EoAT in ayaw direction relative to the mast.
 7. The method of claim 1, furthercomprising: moving the gripper mechanism from the retracted position toan extended position before said securing; and wherein the grippermechanism is raised above the EoAT conveyor to grip the cargo item whenin the extended position.
 8. The method of claim 1, wherein said pullingincludes pulling the cargo item with a second cargo item stackedthereupon.
 9. The method of claim 1, further comprising: pushing asecond cargo item off the EoAT conveyor with the gripper mechanism bymoving the gripper mechanism along the EoAT.
 10. The method of claim 1,further comprising: wherein the gripper mechanism includes a carriage;wherein the EoAT includes a drive track coupled to the carriage; whereinthe EoAT includes a cam track along which the carriage rides; whereinthe cam track is shaped to move the gripper mechanism between anextended position and the retracted position; moving the carriage in alongitudinal direction with the drive track; and wherein said retractingincludes guiding the carriage along the cam track to the retractedposition.
 11. A method, comprising: positioning an End of Arm Tool(EoAT), wherein the EoAT has an EoAT conveyor, wherein the EoAT includesa gripper mechanism, wherein the gripper mechanism includes one or morevacuum cups; moving a cargo item with the EoAT conveyor over the grippermechanism when in a retracted position; extending the gripper mechanismfrom the retracted position to an extended position where the grippermechanism is raised above the EoAT conveyor to contact the cargo itemafter said moving the cargo item; and pushing the cargo item off theEoAT conveyor with the gripper mechanism by moving the gripper mechanismalong the EoAT.
 12. The method of claim 11, further comprising: whereinsaid positioning includes moving the EoAT with a mast that is coupled tothe EoAT; wherein the mast includes a mast conveyor; and transferringthe cargo item from the mast conveyor to the EoAT conveyor.
 13. Themethod of claim 12, wherein: said positioning includes moving the EoATin a pitch direction relative to the mast; and said positioning includesmoving the EoAT in a yaw direction relative to the mast.
 14. The methodof claim 13, wherein: the mast is coupled to a base unit; saidpositioning includes moving the mast in the pitch direction relative tothe base unit; and said positioning includes moving the mast in the yawdirection relative to the base unit.
 15. The method of claim 12,wherein: the mast is coupled to a base unit; said positioning includesmoving the mast in a pitch direction relative to the base unit; and saidpositioning includes moving the mast in a yaw direction relative to thebase unit.
 16. The method of claim 11, wherein said pushing includespushing the cargo item with a second cargo item stacked thereupon. 17.The method of claim 11, further comprising: pulling a second cargo itemonto the EoAT conveyor with the gripper mechanism by moving the grippermechanism along the EoAT.
 18. The method of claim 11, furthercomprising: wherein the gripper mechanism includes a carriage; whereinthe EoAT includes a drive track coupled to the carriage; wherein theEoAT includes a cam track along which the carriage rides; wherein thecam track is shaped to move the gripper mechanism between the extendedposition and the retracted position; moving the carriage in alongitudinal direction with the drive track; and wherein said extendingincludes guiding the carriage along the cam track to the extendedposition.